Here was my honest response when I read the announcement at EN World that Pathfinder was announcing an MMO: I winced.
Not that I don't think Pathfinder is great, but rather because I do. Making an MMO is hard, expensive, and usually fails in one way or another. I worry that any resources spent on the MMO (and yes, I know a different company is going to be doing the actual coding and artwork, but there will assuredly be some impact on Paizo's operations) will be resources not spent on the Pathfinder game itself. I worry in particular about what the impact of a failure in this space would be for Paizo's financial position, and thus the future of Pathfinder.
D&D Online had a much better known property and Hasbro/WotC money behind it. It's currently a free-to-play and never made the big splash that WotC was hoping. Warhammer online sank like a stone soon after launch. WoW perpetually eats everyone's lunch, etc., etc.
I realize that gaming companies feel like they need to embrace the online world in order to survive. They're right, but I think they often think this means 'make a video game'. I wish instead they would invest more effort in facilitating online play of their existing games. WotC's Online Tabletop has been at 'real soon now' status for some time. Existing 3rd party projects lack publisher support. Meanwhile, ConstantCon shows that there is both demand and a real possibility of success for facilitating online play.
MMOs, because of their shared setting and scripted interactions, can never really match the creativity and satisfaction of a good tabletop game. The need to keep mechanics simple enough to be resolved by an algorithm instead of a live GM limits the challenges and situations that can be offered. New ideas mean new code, which means a limited number of ideas can make it into each release. I'm still convinced that making a professional online product that facilitated chat-based (or VoIP-based) play with shared maps, built-in rule/monster reference and a supported forum for finding gaming groups would keep a lot more gamers active in tabletop RPGs than trying to make a slightly different take on automated D&D.