I bloody well hope they continue development, and it becomes the official desktop/iPhone client. I love Sparrow, and would hate to see it vanish into the "acquired company" ether.
I was hoping for the same. But I think they are not going to do any more development on their Sparrow client according to the latest email they sent to the users.
Sucks for the current paid users, but hey who cares once they get a million more users and many more $$, right?