Viswanathan got off to a good start in the Grand Slam Final in Bilbao, defeating Ruslan Ponomariov in round one to take the early lead as the other game (Francisco Vallejo Pons vs. Levon Aronian) was drawn. They use a 3-1-0 scoring system, so he's off to a pleasant-looking lead already.
Over in the European Club Cup most of the early matches were lopsided and many of the absolute top players took the opener off. Some very strong GMs were held to a draw, but I only noticed two elite players suffering defeat. One was Peter Leko, who was crushed by the (stylistically) wild Dutch IM Manuel Bosboom, and the other - sadly - was Gata Kamsky missing a simple tactic and losing to an FM. I don't know what has happened to Kamsky, who last July was 2763 and has lost more than 80 points since then, but I hope he's able to get back into good form.
Both tournaments' websites can be accessed through this page.