This CVG article points out that there was in fact a point about Vanquish mentioned in the leaked Sony/SEGA meeting from september '09.

Straight from that meeting is this:

Vanquish and Aliens: CM

• Opportunity for PS3/PSP interoperability (see Eidos Batman, Army of Two, Assassin's Creed for good examples). 
  
• If we offer that SCEA would be really interested in having us at their booth next E3.

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So, if the leak is true, it's pretty much confirmed to be SEGA published and on the HD consoles (as the last HD game from Platinum Games was also multiplat). I'm curious to see what might be done with a PSP outing though, hopefully it will be something interesting in its own right, rather than a downsized version of what the PS360 gets.

And please don't fuck the PS3 version over like with Bayonetta.

what PS3/PSP interoperability did batman have?

None to my knowledge.

Maybe they already talking about the Sequel to Arkham Asylum?

YAY, another rumor

Platinum Games?

Expecting a bad PS3 port.

Also this game looks like another version of Halo.

Yay PS3 owners can get another amazing game from Platinum games like Bayonetta.

oh no you are right, this is going to fail, everything that tries to copy halo is automatically doomed.

PSP version of a game targeted squarely at the West? Extremely doubtful considering the PSP's current situation.

I also wonder if Mikami still carries a grudge against Sony?  My guess is Vanquish is ground up 360, Sega will be doing the PS3 port honors, and maybe they'll also hire out some shovelware dev (like A2M) to do a different PSP game based on the IP.

You mean about when he said Sony makes their products unreliable on purpose?