Couple quick questions....
After you download and install it, does it show up in your applications manager??? Menu-> Settings-> Applications-> Manage Applications...
Are you using the free version or the paid version???
Do other 3rd party launchers still work right??? Try downloading a few others and see if they work.
Do me a favor... just check to make sure you have the update. Menu-> Settings-> About Phone..... again just to make sure.
Other ideas.... have you tried doing a factor rest??? I know its kind of a pain with out being rooted, but from what I've read around the forums its seamed to help a few people out with the new update.
If a factory rest doesn't work.... maybe try emailing the dev and see if anyone else is experiencing a similar issue.
I'm assuming your not rooted??? Maybe a trip to your local Sprint store.
Reading from you op that even though you have your eVo set to "fastboot" and its still going through a full boot instead of just a soft boot(fast boot) your update may not have been 100% clean.
Try a hard reset like I suggested above, redownload/install Launcher Pro again. See if that works.
Decks Rom Rules, Other Roms Drool!!!
Thanks for tryin!!!