These posts seem to crop up a lot for some reason, the answer is simple. If you already have equipment the answer is probably "yes," but you can easily check with a profit calculator (e.g.
https://www.cryptocompare.com/mining/calculator/eth)
The question of whether it will be profitable to buy equipment is more complicated, but not by much. Find hashrates for GPUs (or ASICs/whatever) from a site like:
https://whattomine.com/Use a profit calculator to see how long it will take to ROI, and decide whether you think the market will crash in that time.
For example, if you assume Ethereum will retain value for a year (and not switch to POS), it is currently profitable to set up new rigs.
Not exactly. Your will earn the cost of your ETH equipment in 2 years. If ETH price will the be same during next two years. But difficulty will be not for sure. So you will never recoup your costs buying new equipment now except case ETH price will quick rise. The main problem - video cards now cost twice they should cost. Or may be tripple. Slow guys experienced problems with calculator dont realised yet.