I don't know where things are/got-to wrt Google donating servers, but:
Would they be able to donate one of their Search-Appliance thingies?
Even if as a short term measure?
+ It'd allow for daily updates
+ It'd be no coding/dev work for WP
+ No extra software to install on your servers, no extra hardware to look after
+ Look n Feel could be customised, and I imagine it could even live
under it's own wikipedia subdomain
- Would involve Google crawling the site again
- Might not deal well with older revisions / seperation of meta pages etc.
If there is a philosophical objection to the "non free" java, I can at
least see the potential for concern about doing this, but equally if
we are getting hardware from them for free anyway it seems logically
to get Search customised hardware+service, rather than just pure
hosting hardware.....
And in any event, there is no "lock in" if you ever wanted to revert
to a different implementation.