Does RC4 continue to be used anywhere?
RC4 seems to be an option in the SSH1 and SSH2 protocols, so yes, it is still in use as cipher. AES seems to be preferred in most configurations, but "arcfour" is still often used as fallback.

WPA and WPA2 may also use RC4 instead of AES, using TKIP. Again, this protocol was introduced to replace the broken WEP protocol while still relying on the faster RC4 protocol. So it's still often used as fallback in case WPA2 with AES is unavailable, e.g. on older hardware without hardware AES support.