Most likely a smart move by Sony indeed, but I entirely doubt that the WiiU's success is in danger. If Sony wants to implement Gaikai into their next console properly, I'd imagine that changes to development 'n such would keep the system off the market for even longer, givin' the WiiU further extended time to pick up impatient consumers.
The next generation after that however, I can't say the same... If both Sony and Microsod can figure out said methods of cloud gaming in their consoles and Ninty doesn't jump on board properly, the lower price perk that casual families 'n such look for might not be as low in comparison anymore. That situation would almost definitely hurt sales.
Either way, I don't particularly care nor am I excited. Notably lower prices are always nice, but I'm a gamer. I'll keep on buyin' games 'till they become a toy for the rich and the rich alone.