yes, the 2.5 kernel can "hotswap" kernels without a reboot.  This will definately be included in the 2.6 release.  Although I fail to see the real advantage of it (especially for a desktop), wouldn't you have to kill all processes, dump all modules, then swap the kernel?  Is the 1 minute post really that aggrevating?  maybe i should do some reading or get the latest 2.5...
as for the windows partition, if the "umask=000" doesn't work, drop a ",rw" right after it (no spaces).  It might be getting mounted read-only.  check your boot messages.
-t.