Naturally one will be used to store Bitcoin but I already have been doing that for almost a year with my NTAG216 implants. (Google: Bitcoin Implant Man) I tried doing this with the first-gen ring but because capacity was limited I use that as an ICE (in case of emergency) telephone number. The implants are used as Bitcoin Wallets, NFC Keepass unlocker, snooze button for the sleep as android alarm clock (works great with the first gen ring too!) and to unlock the phone (only on my rooted droids though)
What we really want to explore is the possibility use the ring as an 'unlocker' or 'enabler' of smart-contracts as this is where the extra capacity will really come-in handy and both my NTAG216 implants and the first-gen ring just don't have the capacity to do that kind of magic. We can't wait to get hacking!