I voted for 4.1-4.5, and think the show will barely hit that mark. Wrestling on Monday nights is drawing around a 3.5 rating right now, and you are going to split the wrestling audience by having the competition air its show the same time (thus reducing the number of homes . Bret Hart coming back should be a draw for wrestling fans (especially the few who remember watching him and how his WWE tenure ended), which is why I have the rating as high as I do.
To think that RAW will pull a 5+ rating just because TNA is also on Monday is completely asinine in my opinion. People watched RAW or Nitro because they found it entertaining, but because there was competition. The people who stopped watching wrestling didn't stop because there was no competing program on Monday nights, they stopped because they were not entertained. TNA means nothing to them, so having TNA compete with WWE would be irrelevant to them (they probably don't even know who the hell TNA is, and if they saw the Hogan ad, they may think that Hogan started his own wrestling show).
There is an old saying that fits perfectly in this situation. The saying goes "Rome wasn't built in a day." We cannot expect the Ratings to be built in a day, just because of Bret Hart, TNA, or anything. I believe the Monday Night 1-Night Stand will be a great night for wrestling fans in terms of programming, and may be a STARTING point for the next ratings explosion, but the night itself will not be a ratings explosion.