A few things I'd like to talk about are:
- the address space operations APIs, and their page based nature. I think
it would be nice to generally move toward offset,length based ones as
much as possible because it should give more efficiency and flexibility
in the filesystem.
- write_begin API if it is still an issue by that date. Hope not :)
- truncate races
- fsblock if it hasn't been shot down by then
- how to make complex API changes without having to fix most things
yourself.