First, these are some really great board scores. Realize that while great indeed, they are not currently necessary to match anesthesia. Rather than the clear self-selection going on here, I would think that a much better gauge of your competitiveness would be Charting Outcomes.
That being said, suffice it to say that my own board scores were nowhere close to the 250's and I did just fine (ranked #1 and loving my program).
For those newly minted MS4's, if you're having doubts on your competitiveness, for whatever reason, you could always do an away rotation and show major interest in some of the lesser KNOWN programs. From my experience on the interview trail there were MANY hidden gems out there. Programs that the 250-260 Step I folks aren't, generally, going to even take seriously. These programs know that, btw.
If the goal is to match anesthesiology, there is a way to do it barring any glaring deficits in your application.
It does help to be personal and non-retarted on the interview trail (we had one dude interview with us with the weirdest haircut imaginable and our chaiman was like "what's with that guys hair"! (he was basically red flagged....), not to mention the socially awkward).
I'll elaborate on the interview thing. I'll restrain myself a bit here, but let's just say that this is a reasonably conservative field. Dress accordingly and don't experiment with hair styles. Look clean cut. Look sharp. Double check your suitcases beforehand. Don't be the dude showing up without a tie. Don't be the tool with excessively wrinkled clothes. (some is acceptable since they know you're traveling but make an effort). Show interest in the program. Chat with the residents. Have questions which show at least a little effort on your part that you've researched the program/area. Smile. Unless you have a beard or goatee, SHAVE. If you do have facial hair, maintain it well. You can't change who you are and if you're not Mr./Mrs. charisma, then that's o.k. Be yourself but just present your best at each interview.
Those are basics but I swear you'll be suprised how many interviewees will NOT do the above (which are ALL controllable). First impressions are a big deal. I would do the same if you're doing an away at any program of interest....
I stress the above since by now, you can't control much of your application but you CAN control the above which will help you.