I'm have a 4:30 mile PR (But I am not the430miler). I plan on running around 4:03/1:57 for the 1500/800. I am currently in about 4:48 shape. Here's the plan for winter:
Day 1: run to track, 10x400 at 72, run back home (5.5 miles)
Day 2: Run 30+ minutes, with a build-up from 7:30 pace to around 5:40 hold for 5 minutes, slow down. (@ 5 miles)
Day 3: Run to track, 3x2000 in 6:45, run back home (6.75 miles)
Day 4: Run 30+ minutes, build-up to around 6:10-20 pace, hold for 10-15 minutes, slow down. (@ 5 miles)
Day 5: Repeat of day 1 (5.5 miles)
Day 6: Easy run of 45+ minutes (6.5 miles)
Day 7: rest
Total mileage: @ 35 miles a week, though it may be more.
Again, I'm training for the mile and down. I may run a 3K sometime just to see what's up, but I won't do any specific training for it. This is the kind of training I did when I first started running, and I went from 5:56 to 5:03 in six months. After that, I started training with two workouts a week (usually two intervals, occasional tempo) and the rest easy days, running about 50-60 miles a week. Four years of training in this way lowered my mile time by a little over 30 seconds. I am bored to death of running slow miles, which negate the quality of track sessions. I will document my success with this plan as I start racing in January.