While creating the grml ISOs for release 0.3 I'm running same basic patching + compile tests with kernel 2.6.11.
Compiling unionfs 1.0.9 against the new kernel worked like a charme, integration of squashfs2.1-r2 and patch-2.6.11-ck1 was also an easy task. iteraid.patch required some small adjustments (see MOD_*_USE_COUNT macros were
deprecated). Several other patches are waiting for integration.
Remember: if you want to see any special patches inside 2.6.11-grml please drop me a mail [mika (at) grml.org].