He’s sending it for confirmation because otherwise Berwick will only be able to serve until January 2011. If he gets confirmed, he can serve until 2013. It’s unlikely that he will be confirmed if the GOP gets enough seats in November, so Obama is doing it now while there’s a Dem majority and a chance.
This doesn’t undo the recess appointment, btw, it’s just intended to extend it.
If Obama has enough Dems (prior to Nov) to get Berwick appointed for the full term, why use the recess option at all?