Since about phpBB 2.0.4 I'm writing some MODs for phpBB.
For phpBB3 (Olympus) I have four recent finished projects: Advanced Block MOD, Advanced Double Activation Pack, Enable Browser Language Detection and Multiple Newsletters Add On. These MODs I will updated for phpBB3.1 (Ascraeus). But still I'm hoping that at least some of the features of the first three MODs will been added to the phpBB core package. In my opinion all of them are needed and important basic and core features.
My last large project will be the Zoological Association Manager Add On. But I think the first release will be finished for phpBB3.1 (Ascraeus) and it will not come before the end of 2011.