Great proposal, I will donate to the bounty.
-Including a zerocoin-esque feature would be great, even if it's just what aaaxn described above.
-Including certain features commonly requested in BTC would be great. Throwing
Coin Control into the GUI, perhaps M of N support, etc.
-Heck, going the extra mile and throwing in cold wallet support in the GUI (like Armory) would give people even MORE reason to celebrate an alt-coin that is NOT just a copy-pasta with a couple minor changes.
I realize it's quite the laundry list, and all you really want to to is try out this new blockchain idea, which is a great idea, but also think of the potential success of an cryptocoin that really "Gets it right" - not just with one major innovation, but that major innovation with a few key features that folks are really looking for.
If you release a copy of the bitcoin-qt/litecoin-qt client with the only change being the smaller blockchain... well, it'll be simple, but it won't stand out quite as much as if you spend some time putting in some great features that people have been asking for in BTC for a while.
The problem with alt-coins is not just that they are copypasta of the bitcoin concept, but also that they are copypasta of the CODE, complete with spaghettification and ugly external dependencies and magic numbers. Many people have called for completely reconfiguring it to comply with good coding practices, and reduce the risk of nasty bugs that might show up later on. I know this is not your intention, to change too much at once, but anything you can do to this effect would be welcomed by the alt-coin community who, after FTC and CNC, have had it up to here with pointless copypasta introduced entirely for speculation. I think if I run another ______-qt executable that shows the same flash screen, same GUI, with no new features... I will facepalm.
A major back-end change like what you've proposed with the blockchain
almost makes it forgivable.