regarding the mmcplus52mhz enhancement, apparently the 200639 kernel will work just fine on a 49-2 system:
http://www.gossamer-threads.com/list...rs/23241#23241

but anyway if you want an updated 200649 kernel:
fanoush posted to this forum (but does not actually list on his site)
http://fanoush.wz.cz/maemo/zImage-yuv420
1276624 bytes
md5sum is 12434779377540ec1f3c7bfa394e44b5

It is based on kernel source from latest IT2006 FW (.49) with high speed mmc patches, multiblock MMC writes enabled, extended brightness control, yuv420 patch and tearsync backport. I am using it on my device for one week or so but better treat it as experimental kernel :-) You can even use linux flasher to load it temporarily without writing to flash (flasher -l -k zImage-yuv420 -b) and next reboot brings your old kernel back

(quoted from here
http://www.internettablettalk.com/fo...05&page=48#475)