I'm not generally a big believer in mobile payment solutions for developed-world countries.
Cash, cards and online payments already work perfectly well for me and other people, thanks. I don't need to "store value" in my phone, I don't want to scan it across an NFC reader, and I certainly don't want my operator bumping up inflation by taking a slice of everything I spend.
I especially don't buy the "bill it to my phone bill" concept of mobile payments - like many people, I have a very different relationship with my bank & my telco(s) and I'm quite happy to keep it that way. You'd have to be crazy to have a financial-services arrangement with an operator which tied it to an access account provision, although if it was access-independent it might make a more sensible proposition. There's also no way I'd exclusively use my phone for payment when travelling, unless all the transaction data was very explicitly zero-rated for roaming, and I had a guarantee of 100% coverage.
I'm also very happy with my existing payment mechanisms - Visa, Paypal, Mastercard, Amex and so forth. I might set up another, but I'd need a lot of persuasion.
But, Sprint's announcement of its mobile wallet solution is much more appealing - you get to keep all your existing accounts, but get access to them through your phone. Makes sense. Adds to what people already have, doesn't try to substitute it. Doesn't stop you carrying a physical wallet around as well as a virtual one if you choose. Doesn't try to bill things to your phone account. Maybe over time, if it's got a good UI and proves itself, you might change your approach to physical payments, some or all of the time. That's fair enough.
In other words, it doesn't force a behavioural change, but works with what people are already happy with. Which is good.
Now it's not 100% clear to me what the business model is, but in terms of "will this fly", my gut feel is that it has 100x the chances of all the various NFC and other mobile payments nonsense that's been trotted out in recent years.
Bottom line is that unlike most people in the industry, Sprint has actually bothered to look up the dictionary definition of a wallet: something that contains various different payment mechanisms from third parties.
Edit - looks like AT&T is also entering the fray. But they are going to go for the bill-to-the-phone approach. Let's see if people are actually prepared to wear that. My money's on "no" - although I'd rather not use an MNO-powered betting application & account....