When should you jump ship? Can you split time between startups & still succeed?
I've been a follower/leech of this community for some time, and I'm hoping to give back at least a pinch by asking a question that will hopefully promote some discussion (while also helping me make a decision... or does that still make me a leech?). Anyway, here's my situation and some background info.

I'm a recent college comp sci grad who joined the big (evil) corporate world. I'm working as a developer on an agile team that's working on a large scale data web application (vague enough?). I started working in Nov and am still waiting for access to actually do some programming. I'm kept busy doing "functional" work. Typical Corporate/govt bureaucracy... and it might still be awhile. While waiting for access, I've been reading HN articles and have fed the part of me that desires to leave the corporate world and pursue the startup venture.

As of right now, I am involved in two startup business opportunities on the side. I have small equity in one of the startups (we'll call it Startup X) - well I signed a draft contract and never received a finalized copy... we'll just say I have equity. The other, Startup Y, hasn't gotten around to actually deciding %'s. Potential red flags? Maybe... I'm new to this realm.

Both startups have been terribly inconsistent. That's actually the reason I initially joined Startup Y. Startup X was super stagnant, and I wanted to code. At one point I think I went 2-3 months without getting any response from Startup X. I don't have a major role in X and am largely dependent on the unresponsive team members to continue with my portion. In regard to Startup Y, I have contributed to the extent I can and am now dependent on another member who is busy with school (who has the knowledge of the complex domain).

Having said all that, here's my dilemma. A guy that I recently met (started at the same company where I work... though in another city) and get along with really well has presented another business opportunity to me. I already feel like dabbling in 2 startups while having a full-time job is not a recipe for success (ff there's one lesson I've learned from following this site, it's that startups don't succeed without commitment), yet I'm intrigued by the newly presented idea. I'm pretty torn.

Startup X is a pretty brilliant idea, and they're talking mondo $$... but I feel pretty uninvolved. I'm not as confident in Startup Y making it, but family is involved and a decent amount of work has already been put in. I've turned down a few opportunities already because of my involvement in X & Y, and I'm wondering when it's time to jump off a non-moving ship. It's really hard to tell if it's a large ship that needs a lot of preparation before venturing round the world or if it's a stranded boat with a broken sail.

So... what would you do? Should I abort X & Y (or just one) for this new opportunity? Should I stick with X & Y? Should I stick with X & Y and also take on Z to see where it goes? The latter seems unfeasible. I know the startup world doesn't have strict rules or a set formula for success, but I'm hoping some experienced entrepreneurs can help a lost soul find some clarity. There are some other details, but I'll leave it at that for now.

I love this community. Thanks in advance.