Too bad my rig can't handle the beta or I'd preorder immediately.
And though the trailer makes the fade look "invicible", trust me, at least in NS1, he def isn't. Fade probably requires the most skill out of ALL the possible classes, both marine and alien, in the game. Your health will drop to 0 in a split second if you're not teleporting constantly... And marines always travel in groups in the game so if you're flying around them they'll just be shooting up everything in a 360 degree circle.
On the flipside, if you're very good at fade, you can kick some serious ***. My best successes at fading (and I'm not very good), were when I had a lerk or 2 spamming poison gas onto the marines position... I swoop in take a swipe and run off. The swipe plus the gas usually will usually kill the marine I went for unless the Marine CO is really quick on the medpack requests. And then of course all the commotion gives the skulks a chance to join in the fun

.
But one really really good fade player can play an entire 30-45 minute match, rack up 40-50+ kills and not die once. Still though, the margin of error is tiny. One mistake and you're toast, especially mid-late game when rines have shotties, HMGs and heavies.
If anyone wants to see what the gameplay is like just go download it, it's only like 125 megs IIRC. All you need is HL1 (what is it, like $2 now on steam

?) You'll get your *** handed to you though by people who've been playing for years.