There really aren't any significant climbs during the bike. That's not to say it's entirely flat, there are sections of rollers once you get off the resort, but a large portion is on sections such as the road around epcot and down the main drive out towards the gate, where it's pancake. What made the 70.3 course difficult for me wasn't the hills, but the wind, which given it's a big loop you'll be staring in the face as much as it will be helping you from behind, and depending on whether the upwind leg is later in the race it might add to the difficulty.
I'm still iffy on the ToT, might get deployed prior to that... I'm waffling as to whether to wear my WISH shirt for the run leg versus keeping on my tri top, it'll be totally dependent on how hot it is and how fast I'm trying to finish. I'm expecting about a 45 min swim, 2 hour bike, and 65 min run or so, might be run into each other on the course? I'll be starting in the 25-29M wave, which for the 70.3 was second to last out of like 20 waves, so I might have a lot of catching up to do...
But here's what to look for!
http://www.gmap-pedometer.com/?r=904697
Edit: Also, here's the 70.3 bike course in Gmaps, basically to get this weekend's course just go straight after mile 19 and skip the little out and back, and then cut straight across from mile 25.5 to mile 41.5 or so on that little road and skip the northern half of the big loop. So mile 1-19 as is, +1 through the out and back, 22-25.5 as is, 41.5-53 or so as I marked it as is. That adds up to 35 miles, and they are calling it 36 which is about right. As you can see from the elevation graph, the elevations go from 100 ft at start, through some rollers mile 17-23 up and down about 50 feet, and now that I'm looking back on it the larger hills were on the northern portions that we're skipping. Last 13 miles or so look close to flat. No worries!
One more way to gauge it, if you look at mile 9 that's immediately following the portion that crosses the overpass to Animal Kingdom, so basically the biggest size hill is similar to just riding over an overpass.