Well, sounds like it is too late for this now since Kaspa is well into retirement. However, Kasparov did try hard to get a return match after he lost to the then challenger Kramnik. As has happened in many times in the history of chess, new world champion was reluctant to do so.
Situation has changed now. Kramnik is no longer being treated as the world champion or as the strongest player in the world. Kasparov was dissapointed (he tried to participate in a match to regain his crown for about 4 years and finally gave up) and retired with his number one ranking in the rating list when he is still the world's strongest player. This is not good for chess. We havn't seen much of Kramnik at all after his brilliant performance in the championship match and now we don't see Kasparov in action either. Only good thing around is that Topalov plays brilliant chess at the moment. Needless to say, Topalov deserves to be theworld champion and he is the worlds strongets active player and also posseses the highest rating among active players.
It's a pity that Kramnik and Kasparov has this unfinished business between them and more so since Topalov havn't had an opportunity to play with either one of them on his way to winning the crown. All we know is that a very recent initiative for arrenging a 're-unification' match between topalov and Kramnik has failed.
I think if Kramnik now offers a re-match to Kasparov we still have a chance to salvage this sad situation. Kasparov has reasons to accept and come out of retirement. (I'm sure he still has fight in him to come and take his opportunity to win back the crown he tried so hard to regain) On the other hand, this is a very good way for Kramnik to come to the lime light again, at the moment he stands a very little chance of competing in a world championship match in the near future.
Hopefully, this will lead to a Topalov vs winner of Kasparov/Kramnik match which will have the potential of being the most exciting match since Fisher-Spassky.
All this is assuming, Kasparov will change his mind and come out of retirement if he is given a shot(I for one, think he deserves it) at the crown. Come on Kramnik, u offered a match to Topalov, why not one for Kasparov? show your generosity and the chess world will love you for it!