For the most part, David Riske had fallen out of favor not only with the fans, but with Wedge himself. Nothing proves this more than 
Wedge's decision to pretty much not use Riske at all down the stretch run last year, using him in only 7 of the final 32 games, and rarely ever in key situations. Wedge just was not comfortable with Riske late in games and in crucial situations because of his propensity to give up the long ball, and falter when it mattered most.
However, Riske did have value to the 2006 pen, and his loss is noted. Regardless of his previous failures, Riske has been a very good reliever and has faired well in a 7th/8th inning role. For whatever reason, though, he just crumbled in the 9th inning or later in ball games.
Losing Riske will hurt, but the addition of Mota will help. Mota is one season removed from being regarded one of the top setup man in baseball. In 2003 and 2004, as Eric Gagne's setup man in LA, Mota went 15-11 with a 2.49 ERA. Mota has the experience in the back of the pen that the Indians can rely on to help offset the loss of 2005 setup man Bobby Howry.
Mota does come with some question marks. The Indians expressed concern over his shoulder in a physical earlier this week. While he did not fail the physical, the Indians felt there was a chance Mota could miss some time in-season due to the aforementioned shoulder, and an elbow injury that gave him problems a year ago in Florida.
Rhodes was a big part of the success of the bullpen for two thirds of the season. In August, he had to leave the team suddenly due to a 
serious illness to an immediate family member, and he ended up missing the rest of the season. All signs pointed to Rhodes being able to pitch this upcoming season.
Rhodes performance as a left-handed setup man will be missed, as he was invaluable in the role last year. His departure likely means that Scott Sauerbeck now is the primary late inning lefty. It is possible the Indians could make a trade or sign a lefty to add to the pen, but more than likely they fill the need in-house. Wickman will still be the closer, and Mota and Sauerbeck now become the late-inning setup men, with Betancourt, Miller, and Cabrera in middle relief. The 7th inning spot in the bullpen will be a battle for the long man spot, in which Jason Davis is probably the favorite. Other candidates are Andrew Brown, Jason Stanford, Kaz Tadano, Jeremy Guthrie, Steve Karsay, and Danny Graves.
In any case, the addition of Mota and a healthy Matt Miller all season, as well as having rookie phenom Fernando Cabrera all year, should offset the loss of Howry, Rhodes and Riske.