Absolutely. Obviously the games are dryer and tougher than 2005-2008 but that was the golden era of poker due to the Moneymaker boom. United States v. Scheinberg, more commonly known as Black Friday, was a huge blow to online poker but it's still thriving due to the rest of the world still being able to play online poker. :)
PokerStars is doing great, tons of promotions, a good amount of fish, lots of games to choose from, and so on. Full Tilt Poker is back up and running and US players are getting their rolls back. There are tons of people making serious money playing online poker. I myself approach it as a part-time job and know quite a few heads-up players like myself that grind out some significant coin.
If you put in the time grinding, studying, and reviewing your play you'll be better than the vast majority of players out there which, over the long run, will result in $$$.
10/30/2014 Update:
On August 1st, 2014, Amaya Gaming Group, completed their purchase of the parent company of PokerStars/Full Tilt. This has resulted in serious changes, some of which I've listed below:
This is causing a major outcry from all regulars/professionals.
The increased rake will result in high-stakes professionals losing tens of thousands, for nosebleed stakes potentially over a $100k, of profit to PokerStars due to the increased rake. I myself, a mid-stakes players, would have lost another ~$2600 USD to PokerStars so far this year if these new rake percentages were in effect. This is likely going to cause a large amount of regulars/professionals to move to other sites or they'll quit playing poker professionally entirely. Amaya is really screwing over a lot of regs with this.
Also, Spin & Gos, which are a HUGE hit among recreational players, are so high variance that it's borderline impossible for any serious reg to make a living playing them, ESPECIALLY with the high rake. As such, this is a serious blow for online poker.
Note that all of these changes are likely due to Amaya trying to get into the US market. Increased fees & rake to pay for lobbying efforts, taxes, etc. Still, they're driving away a huge part of their customer base by doing this. Hopefully things work out in the long run.
Here's an excellent article on how all of this was motivated by the desire to return to the US market, and how it's likely that PokerStars will be back in it soon:
In the booming online poker business, Amaya will raise you billions