Gamasutra posted up an article that has been bouncing around in my documents folder for a little while. The original title was "A Services Strategy for Casual Games", but the new one is a bit more punchy.
One response that I've heard quite a bit is that portals will never allow user data to be released back to developers. This is quite true for most established portals that have traditionally focused on selling packaged goods online. However, middlemen adapt and markets flow around stupidity. More sophisticated variations on sites like http://www.mmoportal.com/ are bound to emerge. If a dozen portals don't want your business, find the one that does. Given time and a exclusive supply of successful games, they'll grow into a bigger fish that can help feed your team.
The portals are engaging in a kneejerk reaction to changing business models. In the long run, do they really think they can keep customer data away from developers when the games that players want are online services? Such companies just end up being a roadbump in the way of progress. A portal that gets irritable about giving up customer data guarantees that their cut of the pie is zero. This is their loss, not yours.