Kernel release status
As of this writing, Linus's BitKeeper tree includes the removal of list_t (once again, see below), a number of memory management changes from Andrew Morton (including the NUMA discontiguous memory patch), more floppy driver fixes, and a number of other fixes and updates.
The current 2.5 Status Summary from Guillaume Boissiere came out on September 4.
The current stable kernel is 2.4.19. Marcelo released 2.4.20-pre5 on August 28; it includes a long list of fixes and a big merge from Alan Cox.
Speaking of Alan, he released 2.4.20-pre5-ac2 on September 4. It includes a number of fixes and a small bit of IDE work, but this prepatch was aimed more at stabilizing things than adding new work.
Alan has also released 2.2.22-rc2. It
contains more fixes than one might expect for a release candidate; among
other things, it contains some worthwhile security fixes.