Sort of, but unless you're really into gaming it's pretty much impossible to identify whether or not your rig is going to meet them. It's not like in the past where it was relatively straightforward.

What's worse the naming schemes for products don't do much to help a person out with determining that. AMD can be pretty bad with the GPUs as moving to a higher number chip might not increase performance at all as they have multiple lines of chips and the entry level isn't necessarily that much faster than the previous generation's top of the line.
It said that I'd be able to run TW2 and it turned out that I was getting about 8 FPS, which is about as completely unplayable as possible.

Those are often just as unreliable. Either the devs wanted to make sure it works and went for high minimum specs even if the game will run on a lot less powerful machine, or the publisher wants to sell as many copies as possible and goes for low specs (on the box), but the game will be barely playable with those.

As Tarnicus said, demos were good for a first impression. They can be unreliable too, and also to both ends. Often demos are compiled before the official release and are thus not as optmized as the finished product. On the other hand in the demo there are often i.e. levels or scenes that are not as demanding as some that take place in the real game (like the demo has 3 varied but smallish levels, while the full game has several huge levels that require a lot more resources). That's always nice. Finally run a game like it looked in that fancy screenshots from the promotions and reviews. Sadly sometimes it's the other way round. New machine and that older game runs like crap because of timing problems. Happened to me with X2 and TDU. And The Witcher 1 also stutters like hell in certain areas (i.e. Old Vizima) although my machine should be able to run it four times in parallel. It didn't lag that much on my old machine.

reviews for gpus are pretty reliables to know if you can run a game or not, I always check guru3d, anadatch etc, they will tell you at what framerate the game runs with your gpu and with that in mind you can tell if you can run the game, most of the games this days use the same engine or they are pretty much the same on pc resources, it's not exact because the rigs they use are probably not the same you have on your pc and they are many factor that will change the performance but it will be close enough.

SysReqsLab never really worked for me. My laptop is pretty hit and miss with what it runs. I've gotten to where I can eyeball it and kind of tell....but the best way is to try it...yeah.

I agree, their methodology is not always accurate. What I truly despise are bench marks videos that I never seem to duplicate on my custom rig 8)

http://www.reddit.com/r/gaming/comments/14h3ra/after_seeing_a_halfdozen_posts_per_day_about_this/

Which is in itself not as simple as it should be. It used to be that you would buy a game on disc, install it, and if your system didn't run it, you could return it to the store. Nowadays, games are either digital or boxed with some kind of account binding, meaning that if your system isn't enough to run it, you're fucked - $50 down the drain.

It was this issue that, prior to the death of my gaming PC, drove me to buy Watch Dogs for the PS4 instead of the PC. My system was simply too close to the minimum specs to make the risk worth it.

Hahaha, ohh yes, I have been there as well. Gaming can be a interesting hobby! It's quite a fun game. I was so happy to be able to play it.

I didn't expect this thread to get so much feedback but I've been enjoying reading the informative posts. I took a long break from gaming for a few years except for a few games like NWN online PW, LOTRO, and replaying old classics so I never really worried too much about my requirements, even as friends would tell me about the latest AAA title or indie that they couldn't stop playing.

i have always found this to be unreliable for me , the thing predicted that games like dragon age 2 , diablo 3 , mass effect 3 , tomb raider 2013 , deus ex human revolution , dishonored would not run on my laptop .
But they ran fine and i stopped using it after this

These things should be somewhat overly conservative, the problem is when they say that rig will run something and they aren't even close.