I know of a few devs that have spoken about P2Pool. I don't know anything about them approaching big Bitcoin businesses.
There have been quite visible attempts to make P2Pool more attractive for miners (earlier in the life of P2Pool), but these attempts eventually lost steam. Recently there have been some attempts to reignite this fire, but I don't see any actual funds or bounties being started, only talk.
I guess I can try email some of the big players and see if I get a response.
It would be interesting to work out how much money would have to be added to P2Pool on a regular basis to make hashers switch.
If it's small enough, it might be do-able for one of the big businesses/exchanges to set it up and manage the incentive programme themselves.