At this point, Rudy being dealt is kind of a foregone conclusion - I wish this wasn't the case - seemed to be so much promise here his rookie year, but doesn't seem like he has ever been happy here and can't see it getting better.
I think he would have been dealt to Minnesota, instead of Martell, if he and his agent would have been receptive to playing there. They have made it clear of the conditions of a team they would be happy going to.
So if Rudy is to dealt, one of two things need to happen. Either the team, who is interested in him, makes the deal despite what Rudy thinks about going there, or Rudy is dealt to a team that fits his criteria: a chance to win, opportunity to play more, and to play in a big market (seems to be a theme these days).
Might be a bit of a challenge for all three criteria to be met, but he might settle for two of the three as there may be a challenge to find a team that has a chance to win (better then 50% of their games) where he would be getting the playing time he would like.
Here are some options that I can think of:
NJ - They have some good young players and seem to be headed in the right direction. They have Courtney Lee at the 2 and could use some outside shooting. They play in NJ for now but are looking to move into Brooklyn. The new owner probably wouldn't mind bringing in an international player.
NY: I don't think they are going to be winning too many games in the near future, but Rudy would like the offensive system and should get a fair amount of playing time and be in a big market.
Boston: Ray Allen just resigned but Tony Allen is a FA. They could possibly sell Rudy on getting some extended minutes behind Ray Allen, if they are looking at decreasing his minutes a bit, and Rudy could look/hope to take over when Ray eventually retires.
Toronto: They are fairly weak at the 2 - drafted DeRozen in the first round last year, but would have to believe that Rudy could get a fair amount of playing time here. They have an international city, could team up with Calderon, but the team may not win a lot - I think they were pretty close to dealing Rudy here on draft day, but the Raptors didn't want to give up the 13th pick - wanting to draft a 4 knowing Bosh was moving on.
Indiana: Maybe an outside chance, however I'm not sure it would be on the top of his list.
Orlando: If JJ Reddick were to leave, this might be a pretty good fit for Rudy - team likes to spread the floor and shoot the 3's.
Miami: I think it's still a possibility, but the rumors seems to be quieting - if the heat sign Mike Miller, I see this as less of a possibility, and not sure if Miami has any more picks to deal away for some time (two went to Cleveland and two went to Toronto).
Dallas: They don't seem to have anyone too strong as a true 2, but not sure if the Blazers want to be a trading partmner with the Mav's.
Phoenix: Not sure how much playing time Rudy would get behind Richardson, but you would think he would like the system. I would trade him in a heart beat for Goran Dragic.
As far as who the Blazers might get in return, if it were NY or NJ, I would look for a pick - perhaps NY's no. 1 in 2012 for Rudy and a no. 2. NY and NJ are both teams that are under the cap and wouldn't have to send anyone back to match a salary. As far as some of the other teams, would have to spend a little more time looking over rosters to see who the Blazers could make a deal for that has a similar contract and would make sense for them.