They will cover you if you're newsworthy. You have an edge if you offer them an exclusive. Launching is rarely newsworthy (unless you're noteworthy as a founder or you're doing something really revolutionary), but growth is-- so start growing and you have a story.
I've been covered on TC 5 times spanning two businesses. My impressions are that A) being worth writing is the important thing and B) It's not all that. 10-15k uniques from TechCrunch isn't going to build your business, it isn't going to get you funded, and it isn't going to get you more than 500-100 actual users. For fundraising (if that's a nearterm goal), it's a good thing. But growth/traction/market are WAY more important.
Real good read on the topic: http://sethgodin.typepad.com
IF you want to ease into it, post a hardcoded signup key here... If it leaks outside of this community, turn it off.