On2 released all the patents they had on VP3 when they gave it to Xiph. Apple and Nokia's patent concerns (if they were genuine) were to do with unknown third-party holders of submarine patents. In that respect, I don't think Google could offer any more protection.

On2 had already disclaimed all their patent rights on Theora.

<video> has already been implemented by everyone but Microsoft (who has no intention to). The Theora issue never impeded that.

Any submarine patent threat that does exist wouldn't be from On2, so this wouldn't resolve it if it existed.