There's always a lot to speculate over when considering the possible outcomes of future events, so I like to entrench my floundering in actual data.
Bernard Lagat ran 12:59 a few years ago, and he's already run 13:03 this season, which is a sign he's in good shape early on. I definitely think that if he got into a fast 5k, he could take down BK's AR. It's just a matter of getting into a fast 5k at the right time. After worlds might be his best chance, or maybe a fast 5k sometime in July if he's planning on runner another before worlds.
It's been 3 years since Matt Tegenkamp ran 13:04.9 and 2 years since he ran 13:07. Last year wasn't a good year to run for fast times, and this year may not be either since worlds are this summer, but he's already started the season off on a good foot. He started 2007 off well also, running 3:34 and 8:07(2 mile AR) before mid-June, but his best at 5k that year was 13:07. Again, that was a world champs summer, so maybe he could've touched the 13:00 barrier. After his first bout of altitude training though, one might expect Tegenkamp's level of fitness to have increased some, particularly his aerobic power. And it is encouraging to see him running as well as he is considering he has to miss a number of consecutive weeks of training due to injury. One thing I am curious about is whether he has the A-standard for worlds, because the best he ran in 2008 was 13:22 and the best he's run so far this year is 13:22, but i believe the A-standard is 13:20. If it is indeed true that he doesn't have an A-standard, I could see where maybe he tries to push the pace at USA outdoors to try and kill two birds with one stone (make the usa team and get the A-standard). This may be the case anyway, as there are a handful of runners very capable of running 13:30 pace, but kick it up a knotch, and him, solinsky, famiglietti and maybe a couple others could seperate out the men from the boys. Considering Tegenkamp has already run 7:37 and they're still training pretty heavily, I think we could see Tegenkamp uncork a 7:32 sometime in July. That's no BK time, but it'd definitely be a sign that a fast 5000m time could be in his future sometime after worlds.
Chris Solinsky is pretty much in the same ball park as Tegenkamp, in my opinion. Their PR's are a little different, but they train together, race together, and their times are pretty close to each other. Solinsky seems to be making a better go at his training this year than last. He mentioned in a runnersworld interview that he's lost about 10 pounds since last year, due to simple changes in diet and eating habits, and I think it's shown with his encouraging early performances (13:18, 7:37). Solinsky already has the A-standard, so he doesn't have to worry about chasing that this summer, which means he can focus on training and just being ready to race with anyone. I think Solinsky will definitely be able to run sub 13:10 this season, possibly even approach the 13:00 barrier, but I don't think we'll see him breaking it in the near or distant future.
Galen Rupp has had a pretty good senior year. He ran the 13:18i AR in early February along with a 7:44i also in February, so I would imagine he's approaching top form about now. His middle distance speed has been one of his biggest improvements this year, so it wouldn't be surprising to me to see Rupp competing with the likes of Tegenkamp and Solinsky at 5000m (not that Rupp is planning on running that at outdoors, but if he chose to, I think Rupp could give those guys a run for their money). I don't foresee Rupp running sub 13:00 this year, even though his focus is probably on the 10k which means he'll probably jump into one or two 5k's before worlds, and they may be fairly fast 5k's considering they'd almost have to be in Europe. I do, however, think that a sub-13 5000m could be in the cards for Rupp in the next few years. He's still really young, so I give him a window of about 4 years before he misses his opportunity to run sub-13, because unless you're mid-distance specialist or talented like some distance runners, it's hard to keep good leg-turnover for a number of consecutive years. I know Rupp's future probably lies in the 10k and longer, but considering this past years performances (1:49i, 3:57i, 7:44i), I don't see why with some more work on his mid-distance range he couldn't become more of a 5k specialist. Just food for thought.
Anthony Famiglietti has also had a change in hear about diet, and although we haven't seen him race a lot this year, I think he's preparing to show us something special. He ran 27:39 earlier this year, which I think was off the pace he was shootinf for, but he still in good shape. He also won the US 15k road champs, outkicking Tim Nelson who also ran 27:30's for 10k this year. We've seen Fam run 7:41 and 13:11 before, early on in the season(2007?), so maybe we'll see some more of that talent come out this summer. He's qualified and on the 5000m entry list for outdoors, as well as the 10,000m list and 3kSC. I don't know which he'd have a better shot at making, probably the 3kSC, which I imagine is the event he will focus, but who knows. I don't think we'll see Famiglietti get close to the 13:00 barrier, but he's definitely capable of approaching it(sub 13:10).
Since USA gets to be sending 4 qualifiers to worlds this year for 5000m, Lagat being one of them, I'm going to say the other three to make the team will be Chris Solinsky, Matt Tegenkamp, and Brandon Bethke. Bethke showed some decent speed (3:42) early in the track season, and he has a 13:27 to his name which he ran a week after his 3:42. I think Bethke will show up with the strength and the speed to finish hard with the big boys. Also, I don't think Rupp or Fam will be running the 5k, otherwise I would've given the 4th spot to one of them.
P.S. Chris Derrick, Hassan Mead, and German Fernandez may not be running outdoors, but I expect to see these guys competing for the 5000m team in the future, and seeing them compete for hardware in the finals at world championships. 2012.