If Sega merges with Sammy, Sega will go under Sammy's Management.
Sega's in financial trouble and Sonic is their biggest franchise, it only makes sense for them to make it multiplatform.
Sega has announced the least non-sports games for XBox, there's no need to worry about that.
The Playstation 2 by far has the largest userbase, it's a sound business decision to release Altered Beast and Vectorman on that platform.
Petitions will do nothing, don't waste your time.
Sega will obviously announce more, new, games at E3, don't make up your minds one way or another until then.