[the_arcadian]

This is a really important question and one that MBAs miss all the time (speaking as one myself). The value of a tech company isn't in its existing product portfolio and revenue stream, it is in its ability to create and launch new successful revenue-generating products in the future. Personally I do think Google has that history, starting obviously with Gmail, Maps, etc. But nobody can predict whether that will continue or if they'll end up like an IBM or Facebook, largely dependent on their legacy products.