Big, mainstream 3rd party developers should just stay 3rd party imho. Us gamers don't benefit in any way from such studios to become 1st party.
What I do support is acquiring distinctive talented start-ups that could improve the 'personality' of the brand. It's a shame that the relationship with ThatGameCompany didn't really pan out (I believe they were close to bankrupt at Journey's release), because having a studio like that as 1st party would've been something I'd like to see.
But let's not forget that many studios just don't want to be bought, but want to stay independent.










