I think the Australian Open suites Agassi more then it does Federer, and the opposite at the US Open which is a faster surface.
Let's take Pete vs Andre. Andre beat Pete at the Australian Open in 2 very big matches which you could see Pete wanted to win very badly.
Pete beat Andre in all their matches at the USOpen, suggesting that Andre was better on hard court slow vs hard court fast.
Now if Andre can beat one of the top 3 players of all time in their prime at the AusOpen, surely he can beat Federer.
I hope the collide...
Keep in mind Sampras was dealing with a personal tragedy in 95, and was injured in 2000. That is not to take anything away from Agassi's wins which were tremendous, but just not to say had they played a couple more times Agassi neccessarily would have won those as well.
By the same token Agassi had some bad luck at the U.S open. Playing a very late match in 95 before the final, a very physical match with Becker, not enough time to recuperate. Same in 2002 with Hewitt.
So perhaps the head to heads had alot to do with circumstances, not the extreme difference in relative abilitys between the two surfaces.
Secondly although Federer has not been around long enough to be "one of the top few players of all time" yet that does not mean his level of tennis is not as great as the top few players of all time in their primes, in his current form. I believe it is. In fact Federer's ground game is much better than Sampras's in my opinon which could make him a tougher opponent, in many ways than Sampras in some ways. Sampras had to charge at every opportunity to have a chance, Federer does not. Also Federer plays the return games with full intensity throughout a set, while Sampras went through some of them lazily at times.
Thirdly Agassi is not really "in his prime". I would never suggest Agassi is better now than he was in 95 and 2000, although he is alot better than 96, 97, 98, but he didnt come close to winning those years.
Plus he potentially is injured, and it may show up when he plays a real oppenent who actually puts some power on his shots. No disrespect to one-year top-tenner Schuettler and one-time slam finalist Schuettler but he hits very moderate(not weak just not puncuating in any way) shots, with a rather weak serve(he seemed to have trouble getting it over the net at times, how he looked pre-2003) and no net game, and the only reason he might be in the top 30 for years to come is great determination and fight which will get him through many a weaker-willed opponent or fellow weaponless/limited type players. It will be interesting to see how his injury holds up if he is forced to exert himself against a more foreful player in the coming rounds.
Overall I just dont see Agassi or anyone likely beating Federer. That being said if Agassi does beat Federer I hope he takes the title. I will be a bit upset with him(I am a Roger fan I admit)but not enough to not cheer for him to keep Hewitt and Roddick from that title. I believe the winner of that match will win the tournament, personally I believe that will beat Rogi, but if not it will be Agassi.