I am new to Ripple discussions so can someone answer these two quick questions please:
1) Why would banks like Ripple/XRP?
Banks don't have interest in XRP, and we don't expect them to. They do, however, have interest in Ripple as an efficient payment system for fiat currencies. There are specific problems they have that Ripple can solve.
2) Why would banks liking it be a good thing?
It's the same reason the military liking the Internet was a good thing. Ripple works better for everyone if there's significant liquidity in the network across issuers and currencies.
Let's take a step back for a second.
Ripple is basically a universal payment system where people can issue, redeem, hold, transfer, and trade arbitrary assets denominated in any currency. To make payments works, Ripple uses a pathfinding system as a kind of "matchmaker". If I hold Bitcoins and want to pay someone in dollars, the pathfinding finds some person or combination of people willing to trade US dollars for my Bitcoins. The payment takes place atomically, so there's no risk of default by an intermediate or being stuck with an intermediary asset. This makes all the liquidity usable.
When we designed Ripple, we basically threw away everything we knew about how the financial system actually worked and designed a completely generic platform for assets. We took the public database with cryptographically signed transactions arbitrated without the need for a central authority from Bitcoin.
You can use Ripple as a payment system without knowing anything about XRP. You just need a very small amount of XRP to cover reserves and pay transaction fees. We expect $10 worth to cover a typical account's needs for many years. We hope that XRP will be useful as an intermediary asset. XRP has no counterparty and can flow between any two account. Other assets on Ripple have a counterparty (the issuer of the asset) and can only be held by those who have agreed to trust that counterparty.
A key difference between Ripple and other systems where a counterparty holds your assets is that people who have chosen different counterparties can still freely pay each other. When you use PayPal, you trust PayPal to hold your dollars and pay you out when you receive payments. But you can also only make payments to and from people who similarly trust PayPal. With Ripple, I can choose to trust SnapSwap to hold my dollars, but freely make payments to and from people who have no relationship with SnapSwap whatsoever.