Of course that services have a strong interest in staying on the branch that's more professionally supported by developers, so yeah, if most of the core team goes to one side, we could predict most of these services would too.
FWIW currently the majority of the core team members, Gregory Maxwell, Jeff Garzik and Pieter Wuille, have all stated they are against increasing the blocksize as the solution to the scalability problem. Each has different opinions and degrees of course on exactly what that position constitutes, but ultimately all of them believe off-chain transactions need to be the primary way to make Bitcoin scale.
EDIT: to be clear no-one, including myself, thinks the blocksize must
never change. Rather achieve scalability first through off-chain transactions, and only then do you consider increasing the limit. I made a
rough guess myself that it may make sense to raise the blocksize at a market cap of around 1 trillion - still far off in the future. Fees in this scenario would be something like $5 per transaction, or $1billion/year of proof of work security. (not including the inflation subsidy) That's low enough to be affordable for things like payroll, and is still a lot cheaper than international wire transfers. Hopefully at that point Bitcoin will need less security against takedowns by authority, and/or technological improvements make it easier to run nodes.
As far as I know Wladimir J. van der Laan and Nils Schneider haven't stated an opinion, leaving Gavin Andresen.
I think Jeff Garzik's
post on the issue is apropos, particularly his last point:
That was more than I intended to type, about block size. It seems more like The Question Of The Moment on the web, than a real engineering need. Just The Thing people are talking about right now, and largely much ado about nothing.
The worst that can happen if the 1MB limit stays is growth gets slowed for awhile. In the grand scheme of things that's a manageable problem.