There will be a Hubble Space Telescope meeting at NASA HQ next week. Among the items to be discussed is a new solar activity model which some people at NASA think will allow the Hubble to remain safely aloft for quite some time after a reboost from the visiting shuttle.
This way, so the thinking goes, the hope is that a deorbit module i.e. the PDM (Propulsion Deorbit Module) will not need to be included on the SM-4 mission. Apparently, a few weeks ago, when Mike Griffin was briefed on Hubble, an estimated deorbit some time in 2030 was mentioned. According to a participant Griffin said something to the effect of "why are we worrying about it then?".
Deleting the PDM solve some vexing upmass issues. It would also save NASA a large amount of money. Not only would the PDM not need to be developed, but money would not be needed to modify the FSS (the payload carrier that holds Hubble in Shuttle's cargo bay) to accomodate the PDM.
Of course, the issue of bringing Hubble back will have to be addressed someday - but at least it won't have to be dealt with during Mike Griffin's time as Administrator.