Another reason is that it would totally ruin any sense of immersion if you're playing a sci-fi game on a console that's far more advanced than the technology depicted in said game.

Here are some possible reasons why it may not come to ps3.

1 Its possible microsoft still has a deal with bioware over the console version of the game.

2 Its possible microsoft is paying bioware and EA to keep it to 360 and pc but I kinda dought it.

3 This what I think now is possible,I hear microsoft still has control over the console version of ME1 and bioware does not want to release the second one without its original on the platform. Games have still released sequals without the the first one not being on the system like dead rising 2 and saintsrow 2 but those games were not that big on story at least from what we know of from dead rising 2 and bioware cares alot about story and MEs is a big part of it.

What I think is wierd is that why hasnt EA just have an internal team port it to ps3 like they did with Dragon age origins because its also been said that DAO would have only been on pc if werent for EA wanting it on the consoles,so we really dont know the reason why but their must be some kind of road block preventing EA to port ME1 to ps3 and that reason alone might be why it wont come to ps3,what do you guys think?

Two possibilities:

1) There's some loophole in the contract which they're thinking of exploiting.

2) If they just said "NO PS3 VERSION", then there would be one set of articles, and nothing else. If they keep it mysterious, there are articles every time they drop a hint. It gets the game more coverage.

Half the games there weren't exclusives at all, they made a huge fuss of MW 2 timed exclusive DLC, so only timed exclusivity would not remove it from their E3 schedule. EA probably wanted to keep it for themselves

but if it was a big exclusive like splinter cell(that was shown) why wasnt mass effect 2 shown? both splinter cell and mass effect 2 are 3rd party games, so mass effect 2 would have been shown if 100% exclusive.

in fact if mass effect 2 was exclusive then it should have been shown instead of splinter cell, previous SC was multiplat, but mass effect wasnt.