What kind of role would be looking for on "Wall St."? A lot of the companies on Wall St. have a large variety of roles and, depending on what position you're looking for, certain programs might be a better suited to get you where you want to go or an MBA may not be required at all.
If you're looking to get into investment banking (IB) or private equity (PE) it may be difficult (although not impossible) without prior experience. From all of the people I know in those industries, they either had prior experience before getting their MBA's or worked in a closely related industry. Also, immediate post-MBA salary in IB and PE will not be far from what your salary is today (but the bonus may be substantially more) and your colleagues will likely be much younger than you.
There are also other areas of Wall Street such as sales & trading (S&T), buy-side/sell-side equity research, and portfolio management. I've heard of people career switching into those industries however it does require a good amount of networking, but if you get into and attend the right program those connections may be available to you. I know an individual that graduated from the Cornell EMBA program and successfully transitioned from pharmaceutical sales to buy-side equity research through some amazing networking.
Lastly, I'd suggest doing research on the web for companies and positions that might interest you. WallStreetOasis (WSO) and LinkedIn are great resources for this. You can find the qualifications and skills you will need to obtain the job you want by looking at job postings at Goldman or even looking at people's profiles on LinkedIn. I recently finished Michael Lewis's "Flash Boys" and there's an interesting part where they used LinkedIn to find the small network of guys and skills in the HFT industry. Who knows, maybe you can find a "Wall St." job without an MBA at Knight Capital or Virtu Financial (about to go public). They're always looking for high end CS and IT guys to write trading algos and engineer faster networks respectively. However, it may not be all that different from what you're doing now, just with a different paycheck...
Sorry for the rambling...but perhaps you need to find out more specifically what you want before you take the next leap.