I installed it on my I537 last night (or earlier today, I honestly can't remember, bleh) and set everything up but a) I don't have a legit Samsung battery at the moment so no NFC capability anyway (real battery should be here tomorrow, actually), and b) after reading up on the device support at Google's support site it looks as though there are two primary requirements for Google Wallet to function:
1) a device with NFC that is supported by Google Wallet
2) a carrier that supports Google Wallet also
Now, looking over the info again at the following link:
it does show that the Galaxy S4 is eligible which should mean the Galaxy S4 Active is included as well, it's the same basic hardware for the most part
but, the issue then becomes is your carrier one that supports it, and according to the info on that page the Galaxy S4 (and by similarity in hardware, the Galaxy S4 Active) is only supported for Google Wallet using Sprint, US Cellular, and Google Play
so if you're not using one of those you're/we're out of luck - I use T-Mobile and will test out Google Wallet over the weekend with the new battery. I get why Sprint and US Cellular are mentioned: because they ARE cellular carrier providers, but Google Play isn't so that's somewhat confusing why they'd mention it specifically.
Oh well, hope this clarification helps. I'm sure as time passes more carriers will get on board with Google Wallet - once Google starts pushing that aspect hard, other companies aren't going to have much choice but fall in line and provide support.
It's Google we're talking about here...
Currently in between devices...