A quick list of what lacks now. Guess that CSSU with 'Maemo Reloaded' gives the best prospects

qt 4.7.4 for autobuilder - for libmeegotouch 0.26

newer libc6, libpcre3 8.x (built, not testes 'nuff) - for timed and qmsystem2

tracker - requires glib 2.28 and should greatly improve the system performance. - for qtsparql and share-ui, transfer-ui, accounts-ui

libx11, libxi6, libxau6 and the whole family - for games like (first example off my head) Icy Tower. Plus it might improve the overall system performance.

Qt Mobility 1.2 system wide would be useful for libcontentaction - I didn't find a way to reuse qtm12. And qtm 1.2 system-wide would fix some of the runtime errors (no need for LD_PRELOAD)

debhelper 8 - for some lib, iirc for libquill

Something in Fremantle is messed up and in Nemo isn't - meegotouch has problems on Fremantle (take mtermite as a non-complicated example or meecast for Harmattan which uses only MGonf iirc.)
The meegotouch examples work though... And some apps mysteriously segfault in 0x0000000. (And all/most Harmattan apps can be run in Nemo). So it's Fremantle-specific

meegotouchtheme-graphics (needed for libmeegotouch) break qt-components-10. (Icons are totally borked) I'd need some feedback from Qt Components developer, and inean was there half a year ago.

libdsme0.2.0-meecolay could be merged into libdsme, but it doesn't replace our dsme cleanly. But I have no idea whether newer dsme in /opt/meecolay breaks any Harmattan apps or not.

About the segfault: try to gdb it and tell me the result

/edit: and sqlite3 >= 3.7 is required for accounts stuff. And if accounts should be in extras, I'd need it for building