In a job rut, should I stay or should I go?

I am working for a great company with a great job as a marketing manager. However, the opportunity to deliver that big bet win is null and void, despite my past experience.

I want to seek another role within the company, but I worry that they will feel I don't have that major win in this current role that would make me more marketable.

A project (building a community website for our Tier 1 customers) just fell into my lap (FINALLY) that could help me go to the next level. Should I stay long enough to make a great impression with this project, THEN leave? Or get the H-E-Double Hockey Sticks out of Dodge, before it's too late?

P.S., most of my teammates are jumping ship NOW before we go through our annual review in the fall. I worry I may be leaving too soon, yet not soon enough.

If you are good at what you do, and it sounds like it to me, then I would build the drive inside me to deliver a world beater result if I had the chance. You seem to be worried about good impressions and getting other people to think you are good at this stuff. If I can rather boldly make a suggestion.... Get over it! If you are good, do stuff that makes YOU feel good about the result. Forget what others think of you, do what YOU know is right. If you love what you, tell the rest of them to stand back or get trampled.
How would I know? I had poor education and easily retired just past 40. I had a few mottos I lived by. 1. It is never the things you do that you regret, it is those you dont. 2. Run until tackled. (that is, make decisions until someone tells you to stop, and guess what?) 3.You can only change tomorrow, yesterday has gone.

Good luck, get going, get angry, get results, Jackson.

I totally agree with what Trevor said.

I would also add, however, that the best time to look for a new job is while you still have your current job. You will come across as being more marketable, plus, you will be less tempted to accept the very first job that comes along if you are at least able to meet your financiial obligations (which includes keeping gas in that piece of crap Altima you drive).