Wooohooo! Congratulations to us!
Chris - I know exactly what you mean. Aside from the heat, I also felt there was something in the taper that affected my performance on the day. I still don't know whether my quads were sore after only the first 10km because of the (admittedly not particularly deep) sports massage I had three days before the race, or because during the two week taper my quads lost their newly-acquired susceptability to long slow running. For example, after my 20 miler, my quads were quite sore, but by my half marathon the following weekend, they recovered much more quickly (even taking into account the fact it was 6.9 miles shorter). I felt as though I 'lost it' more quickly than I had expected to.
As for training - I followed the RW sub-4:00 garmin schedule to the letter over the last six weeks, aside from one long midweek run being about a mile shorter than it should have been, running 5 miles instead of 10 on the final Sunday before the race, and not running the 2 miler the day before. Otherwise, all went perfectly to plan. My 'marathon pace' increased during this time too - originally I was running at about 5:45/km (9:15/mile) for marathon pace, but became quite comfortable running at a marathon pace of 5:20/km (8:34/mile).
In other news, I didn't quite make it to the pool yesterday - ended up watching 'Without Limits: the Steve Prefontaine story" on youtubem which was quite gripping. Am heading up to the pool with a book shortly though. I fly to Sydney tonight!