Iota isn't much more than a whitepaper and a centralised PoC. Supposedly they're supposed to roll out the real thing eventually but given their track record and how they've responded to criticism in the past I'm pretty skeptical.

I'm also very skeptical of Skycoin and their "web-of-trust" which is even more experimental than "proof of stake" which is itself rather unproven at this point.

Reading through the whitepaper I also feel like Skycoin has an issue that's shared with many newer cryptocurrencies trying to break through (including IOTA) which is to attempt to do way too much stuff at once. It's just just "web-of-trust", it's also "skywire meshnet", "fiber application ecosystem", "Skyminers custom-built hardware VPN" etc... In an effort to differentiate themselves they just pile the features on top of each other instead of focusing on doing one thing right. At least they don't use ternary I suppose.

It seems like a very wild bet to me (even by cryptocurrency standards) than either of them are going to manage to replace Bitcoin by the end of the year. After all, what drives adoption at this point is mainly speculation, not the features otherwise Bitcoin would've been replaced long ago.