If your electricity price is low, you can mine profitably on Ethereum. But if you have to buy GPU and PC system, you might not get return of investment. The Ethereum mining might last 10 more months and become PoS later.
Agreed — ETH is a/the hot commodity now, price has risen dramatically in the last month and makes it mildly profitable in the short term if you convert to fiat, but things can always go to pot quickly with any new altcoin. I do think ETH has a lot more technical legs under it than others, but others still persist and are rising too (DASH for example). To me, when you see kraken.com exchanging ETH directly to fiat already, there must be something to it.
ETH mining rental service(s?) jacked the network hash rate up over 600GH of late, but you can still mine ~.7 ETH/day on a desktop with a low-power GTX970, based on current exchange rate @ $2.50/ETH (see my summary here:
https://bitcointalk.org/index.php?topic=1275226.msg13725983#msg13725983 ).