I don't blame Drogba for leaving he's simply seen the writing on the wall. Now that Abramovic has gotten his beloved trophy he has little reason to accommodate the Geriatrics anymore. Meaning next season will likely see most of them benched whilst they try to inject youth. My guess is Mata will now play behind Torres, Marin on the left, Ramires right, and Mikel and Romeu central.
In China, Drogba will earn more money and walk into any first team without even breaking a sweat. Plus Anelka will be there to host him.
As for RVP i'm very doubtful he'll stay. Mostly because we've been down this road many times and the player almost always exits in the end. I don't see Wenger splurging and buying players to RVP's content...nor do i see him pulling a SAF (managed to keep Rooney/Ronaldo against the odds). If the player is proving difficult Wenger won't hesitate to sell/discard.
RVP is ageing (29 as oscill pointed out) and for the first time in a while he's injury free AND in-form. Hence he wants to seize the opportunity to win something before its too late. The best bet for that sadly isn't Arsenal right now but rather City, Utd, Chelski, Madrid or Barca...which is why i expect him to exit the Emirates after the Euros.
Then again if Wenger does indeed buy
M'Villa,
Hoilett,
Kagawa,
Sakho etc as rumours suggest then who knows...not holding my breathe though. We'll likely be fed the "we already have players coming back from injury and i believe in my team blah blah blah..."