I try to answer to your questions, also if you must think that are only opinions. I can be more precise about Kemboi and Bungei, that are athletes of my group (Kemboi is coached by myself, Bungei by Gianni Ghidini).
1) Nicholas surprised me too in improving so hard. I was his coach from the end of 2000. He already demonstrated to have very good possibilities, reaching 4th place in WCCCh-j in 2001, and was able running in 13:26 5k, but never gave me the idea to be so strong. Also this year, he had a bad winter season due to an injury, so I preferred to move him to longer races, thinking of a future like marathon runner. He ran in 62:16 his first HM in Portugal, then 60:31 in Lisbon. After a period of recovery, prepared the track season, going to Hengelo in 10000m where ran 28:19. Soon later, he reached me in Switzerland (Davos). I soon realized that he was not well prepared, so I spent 3 weeks in volume and basic training, without using speed works. He went to Sotteville in July for 5k, and ran 13:42 arriving 5th (5 people together during the last lap), then went to Algier running again in 13:42 (Moses Mosop won with 13:39) arriving 4th (5 people together during the last lap). This situation confirmed me that he was not fast in the final, so my idea to move him to Marathon was stronger.
The key happened during a work at the end of July, when I porposed 5 sets of 600/500/400/300/200m alternating speed (sets n. 1-3-5 in 1:30/1:20/58.0/46.0/27.0 with 1:30 recovery, sets n. 2-4 in 1:36/1:12/62.0/41.0/29.0), recovery 5 min between sets. The group was Nicholas, Kwalia, Mosop, David Kilel, Abel Cheruiyot and Nyamu, and the winners in Youth Ch. (Choge, Ronald Kipchumba, Samson Kiplangat and Justus Kiprono) only for 3 sets.
I permitted the last 200m free : Nicholas ran in 23.2.
So, I called him : "Nicholas, how is possible that, when you are 5 athletes in the last lap, you are n. 5 ? You are fast, why you are not able to sprint ?". He told me that was not good in sprinting. I spent 2 hours in speaking with him. After few days, he went to Heusden for pacing 5k till 3000m (7:52), then stayed inside the group and finished 3rd in 13:14.41. On 10th of August he went to S.Sebastian, competing for winning, and was n. 2 with 13:14.33 after beeing in front last lap, but finishing to push last furlong as he took a small distorsion on the border of the track. But at last he had understood. In Zurich he ran last lap in 55.2, almost winning against Kibowen in 13:01.14. So, I decided to train him very hard for two weeks, for preparing 10000 in Bruxelles with the goal of 26:45 that already seemed to hard.
Nicholas can be the new Gebre, more than Bekele, that has different attitude. Like Gebre, Nicholas can go to the Marathon in the future. Like Gebre, he's very light in his body and in his action. Like Gebre, in the future he can run 1500m under 3:35.
Bekele is unbeatable in cross, having a muscle power bigger than other athletes. He has a very high level of Aerobic Power, but I don't think that can move to longest distances like Nicholas.
2) Eliud Kipchoge is a runner that can last. I prefer him to Chebii, because he is more aggressive and doesn't afraid about anyone. Chebii never "made" the race, always awaiting the pace of other runners, beeing confident in his final kick. I think that Chebii has an Anaerobic Threshold lower than Kipchoge, and a mentality less aggressive than Eliud. I think that his personality is not so big as Kipchoge. Chebii has more muscle reactivity than Kipchoge, but also more fright of top runners, and fears fast races from the start. Personally, I think that Eliud can run under 12:45 already next year, but I see this more difficult for Chebii.
3) Ezekiel Kemboi has very big talent, but is not well trained under the aerobic point of view. He had like coach Paul Ereng, very good coach but with mentality of short distances, and steeple are not a short distance. During the last period, Paul Ereng was no more his coach, so Ezekiel now has also to solve the problem of a top coach for improving. In relation to Stephen Cherono, Ezekiel is of sure very less strong in flat distance. He has to improve very much in that direction. He is already good in technique, and has very much elasticity and nervous capacity of changing speed. But, for winning the main races, he needs to be more resistant at high intensity, for long time.
During WCH in Paris, I planned with Stephen (Shaheen) to start very fast for tiring Ezekiel reducing his final kick. Shaheen was trained to fast races. He made many workouts with change of speed alternating speed every lap (2000m in 59/72/59/73/58 = 5:21, for ex., 3 times with 4 min recovery), and was mentally prepared in following every pace (see the victory against El Guerrouj in 5000m). Ezekiel was only prepared in progressive races, with slow start and terrible finish.
For Athens, Shaheen cannot run, but I don't forget Paul Koech, that at the end of the season was able to improve very much. Koech is, at the moment, more consistant of Ezekiel Kemboi. Anyway, both the guys can run under 7:55.
4) Bungei, coached by Italian Gianni Ghidini, is part of a training - group including also Yiampoy and (from next year) Mutua. He's very serious, follows our system also when is in Kenya, and understood that what is possible to do in Italy (for example, lifting weights and using other training facilities, always followed by a top coach) is not possible to do in Kenya. So, Wilfred (that is cousin of Wilson Kipketer and nephew of Henry Rono : good genes !) lives long time in Italy, from april, and is one of the more professionals runners I know. I don't think that he is inconsistant : he was sick from the end of July, and his last defeats were in a period of big load in training, for preparing World Championships (that could not run, skipping Trials due to the sickness). But, everywhere he had a focus, he was able to reach it. He's now very stronger than two years ago, when was silver in Edmonton. He can be a very good card for Olympics.
5) Edith Masai is a very good runner, but her age probably doesn't permit big improvement in her future. Ethiopian runners are very young, and their improvement is easier. So, I'm disappointed, but about women I think that Kenyan runners have no chances of medal (except for Marathon).