But he was working for Firaxis and now for EA, is he allowed to be consultant for another company?

That was the guy that helped make that shit game called Spore?

There is no such law.  There may be such a clause in a person's employment contract, but that's an employment contract, not a law.  Thus, it's usually a breach of contract lawsuit that's used when there's suspicion of improper IP use, and even then most general development is far too vague to provide grounds for the suit.  Otherwise, programmers would be stuck working for just one company forever, because working anywhere else would leave them vulnerable to getting their pants sued off.

Not that some companies haven't tried it.

Maybe if you went through comparing the source code of both, but in cases like that it's impossible to tell if similarities are down to IP theft or because that coding solution just fit the task best and was used in both independently. The games would still be as different (or otherwise) as ever, that depends on the design brief. If the same game designer was working on two similar games at two different companies then you probably would see lots of similarities.

Language...

He was drafted in to improve parts of Spore.  Its not that bad (DRM notwithstanding), its just that people were expecting it to be the best game ever, which it isn't.

Soren is one of the great unsung heroes of computer games.  'Sid Meier's Civilization IV' would be better titled 'Soren Johnson's Civilization IV' for a start

Say again?

I know for a fact that Meir owns (does he still?) Firaxis (developper) and that Microprose was (closed up when the whole industry trend of corporate fusion started in the early 90's) only a distributor. Maybe it was a sort of partnership situation - unknown to most people.

The rumors you heard about EA buying out everybody else are not real, btw! Blizzard would never agree to such tricky business decision anyway.

Besides, MS could very well buy up front & actually own the whole gaming industrial kalamazoo (X-Box needs a steady input of fresh titles as does Sony for its PS3+, etc) and get away with it - notwithstanding US made hegemony worldwide market "laws" even if enforced.

Don't worry, I know my history

Microprose was founded by Sid Meier and Bill Stealey (I hope I spell his name correct). Initially it was a game developer, then became a publisher. Microprose is old. When I was a child I spent many hours playing Microprose Soccer on the Commodore 64. The last game Sid may have programmed himself could be Pirates! for the Commodore 64.

In the early 90's Microprose got into trouble and was purchased by Spectrum Holobyte. During the takeover Bill Stealey then left Microprose and Sid Meier became the head of it.

Afaik Sid left Microprose to form Firaxis after Microprose was purchased by Hasbro Interactive. I don't know what happened with Spectrum Holobyte.

The Microprose development studio in Hunt Valley was closed after Hasbro Interactive was sold to Infogrames. This also was the end of the Microprose brand.