I was less than happy about the ambiguity of the announcement yesterday. I think we all understand why major players accepting bitcoin has not had an immediate positive effect on the market rate. Depending on how braintree/paypal implement, this may have the same effect on the price. Here are the implementations I can see, and likely they are phases.
1) Accepts bitcoin, immediately converted to USD.
2) Accepts bitcoin, allows storage as either USD in paypal wallet, or BTC in coinbase wallet.
3) Accepts bitcoin, stored as 2, but allowed to fund coinbase BTC purchases with PayPal Balance USD (really no different than withdrawing cash at an ATM, which they already allow)
4) Accepts bitcoin, stored as 2, funded as 3, but allows paypal purchases to be funded by coinbase BTC.
Any implementation past #4 (paypal wallets denominated in BTC) would likely require a paypal buyout of coinbase, which I find extremely likely.
In the future, I think paypal will have its own bitcoin wallet so that we can pay in and withdraw and maybe convert into (from) fiat. That is effectively coinbase or exchange.