I do not know much about big business financials, but this seems like a move that would allow Google to separate its experimental or research-based businesses that do not turn a profit from its giant bulging revenue beasts. It will likely allow Google to post better quarterlies, and push their stock up even higher.

Appointing Sundar as CEO also allows them to focus more on the cool stuff in Alphabet and let Sundar run the meat and potatoes Google operations. Interesting moves.