[rant]Not to be a cold blanket, but I think everyone should make some serious consideration when installing J!1.5.
Just take a look at the amount of problem reports on this forum that are related to 1.5. Pages and pages of them. And it's not just here, it's on almost every other project's forum.
Developers are wasting time trying to figure out what's wrong with 1.5 instead of spending that precious time on their extensions. What makes it worse is most users don't even understand the difference. To them, when something doesn't work, they just go "Oh look, it's broken. Fix it. NOW!"[/rant]