Be aware of one thing: make sure you create your recovery media BEFORE you proceed with the upgrade. If for some reason you want to go back to Vista, you'll need those discs.
Windows 7 will hijack your Acer recovery partition and use it for it's own. This is why you should create the recovery discs... it is better to remove the Acer partition and recreate any partitions you need... Windows 7 will automatically grab the first 100MB for itself (as a recovery partition). Of course, if you replace the hard drive as the above poster did, you won't have to worry about it. I had an issue with mine as Win 7 hijacked the Acer partition, then it decided it would make my D: (DATA) partition a Compaq Recovery partition to make up for the fact it that it hijacked the Acer one.
Needless to say, I backed up all files on the Acer partition(s) and blew everything away to load Windows 7 fresh. I don't have my recovery media, but then I don't plan on going back to Vista anyway.