Google seems to be trying to roll out account switching across all their services. I noticed a few weeks ago that it gave me an option to log in to Google Docs using either my Google Apps powered college email address or my normal gmail account, when both cookies are set as logged in. However, with Google docs there are a few bugs, for instance it seems to log me in to Google docs with my college email address but when I actually click a document it tells me that I don't have permission to access it.
"Since Google Apps customers can already sign in to their accounts at the same time as their personal Google Accounts, we won’t be adding this new feature to Google Apps until the new infrastructure is in place."
I really really wish paying Apps customers got a little more priority than this. It's becoming a habit.
I wonder if they see it as using the free (non-gApps) accounts to vet out the new features first rather than risk breaking paying customers accounts with new features that have random bugs that they did not catch in internal testing.
For some reason, when I click on their link (google.com/accounts) and login, I am directed to "how to clear cache and history" page.... So I searched for multiple sign in, and I'm back to the clear cache and history page again... WTH