According to CNN, Google is prepared to go portal/email service (read basically turn into Yahoo! and MSN.) Not that Yahoo! and MSN are necessarily evil, its just that Google was innovative at one time, and hopefully will remain that way, although once it goes public, its over, so to speak. Once Google has to answer to its shareholders, the time for taking chances is done. They have to deliver value to the Shareholders (Which is part of the problem facing the US today: consumerism.) and as such cannot afford to innovate much, as that could lose money, and losing those pieces of paper with Dead People's faces on them is not part of the game!
Jumping the Shark refers to the old Happy Days episode where Fonzie literally Jumps a Shark. The show is said to have gone down hill after that. There are whole websites devoted to this thing or that thing "Jumping the Shark."