They sure won't write off the whole series when there's more left to milk out of it. And it won't even surprise me if BW brings out a Mass Effect MMORPG in the next couple of years.
It can be fun to play, but i think they should have just done 8 games, each one for each class and stuck to single player, that way they could have kept the whole companion system like Kotor.....perfection.
I mean, with Kotor, i could use any companion combo and still do well on any difficulty, while certain combos were more better, it was still possible with combos that min-maxers called crap.
When it comes to Swtor, the whole companion system becoming a mini-trinity system just ruins the fun and making the performance of your character based solely on its role and your companions, if you pick 2 dps, you will have a lengthy downtime, especially when facing an elite.
I just hope bioware doesn't screw up ME4 with a 3 colour ending or at the end of a trilogy after saying importing a character throughout the trilogy will make an impact.....when it really doesn't make much difference at all.