Probably offer some free advertising and promotion deals, which might be quite attractive to smaller publishers, as that represents up-front expenditures. Perhaps some deferred payments on other costs, or fees dependent on success. I don't know if they'd go so far as to fund or partially fund porting costs but it's always possible. Normally I'd say that a million dollars here and there would be chump change for Microsoft but they've been tightening the purse strings on Xbox lately.
We'll know how negotiations went if they suddenly start running some feature ads and giving prime advertising space to mid-level Japanese games.
On the other side of the coin, that Spencer is handling this himself probably helps. The Japanese care a lot about appearance and signs of respect. However, they're also notorious for business politicking so there is no way to know what will happen.
