Wouldn't be cool if TT ran a contest that allows winner 2 be in a walk in game role
 

Not sure if this idea was presented in this forum before, but wouldn't be cool if Telltale games ran a contest that would put the contest winner in a walk in role? I mean I don't think it can be too hard other than having to make a new character model. It would just be neat and the winner can have bragging rights.

I think you TT guys should discuss about this since it seems like a neat idea or I thought it was at the time of this typing(I am procrastinating on a college project btw)
I mean Telltale may be saving money this way by nothing give us something tangiable as a contest prize. j/k

This may or may not have been brought up before, but regardless it is an awesome idea. I think in the past we have thought of including in-game winner quotes or ideas, but I am not sure if a cameo was brought up or not.

TTG, is this even feasibly possible?

Doubtful.
For starters, not everyone can act or has the right attributes to deliver a good enough performance or at least has a voice good enough. Just record your voice and play it back. Does it sound right? Too high/low?

And second, recording is not as easy as it seems, should TT pay the trip to the studio? What if the winner is not from the US?
Sending a mp3/wav with your line(s) is not an option unless TT spends budget/time editing/de-hissing/filtering/etc the lines for a cameo character.

I made no mention of acting or voicing the character especially because I didn't fathom the notion of doing so. Like you said, it would be too expensive for TT to fly the winner to the Bay Area just to record his/her voice. All I said was to have the winner his/her likeness in the game. For example, make the winner a spectator to a crime scene or whatever or have a wanted picture of the contest winner(drawn 2d in Purcell style or rendered 3d) at the office or Sybil's place. When clicked, Sam would read the sign and say something like " [insert contest winner's name] is wanted in over 48 states and is known for stalking Telltale employees. Beware, suspect is armed and dangerous."

Or TT can probably give that of the contest winner a disguise of Bosco; when you meet Bosco in his guise, I would imagine him(using the va of Bosco) saying something like "Hey gang, it's me, (insert contest winner's name.)" Max would say "Who?" and then Bosco would say "Don't you recognize me? I am your biggest fan. Heck, I won the contest the other day where I have the chance to you."