The best way I can sum up the difference between the Celtics and the Lakers in 2008 vs. today is this:
Boston has turned into more of a "hybrid" semi-transition team on offense. LA has turned into more of a "grind-it-out" halfcourt team on offense.
Boston has lost some of its interior defensive prowess (i.e. less KG blocks), while gaining disruptive defensive capabilities in the backcourt (i.e Rondo and TA). LA has lost some of its backcourt defensive prowess (i.e slower Kobe and Fisher), while gaining disruptive defensive capablities in the frontcourt (i.e. Gasol and Bynum blocking).
Of course, this is all "relative"...and it is not so much that these two teams have "lost" anything. It's more that they've adopted some of the most characteristic traits of each other in formulating their on-court philosophy.
THIS is why a potential rematch between the Celtics and Lakers would be SO sweet. It would epic, not only because it would settle the debate over which team "owns" this 3-5 year period in NBA history....it would also feature two teams that have mirrored each other, followed each other, and modeled themselves after each other without even realizing it.
It's no accident that the Lakers have become more of a "big-man" team...and neither is it coincidental that the Celtics have become more of a "point-guard"-led team. It reflects the changing dynamics present in each basketball conference. The West has gradually grown more physical, less "run and gun". The East has become MORE of a high-scoring conference with teams such as the Cavs, Magic and Hawks...all offensive titans in themselves.
Boston and LA used to represent the defensive and the offensive ideal respectively. Now, they are mirror opposites that do EVERYTHING well.
For this reason, I think that a rematch between the Celtics and Lakers would resemble that of championship series between the two teams during the 80's. Not only are the matchups compelling, but the narrative is too. It is the narrative of the "defending champion", expected to easily reclaim their title and breeze right through the early rounds of the playoffs, only to meet the "previous defending champion", a broken and discouraged team that had been counted out by pundits and experts, all of whom were doubtful in the team being able to get beyond each playoff round opponent. Time and time again, they are proven wrong, and the team gains back the confidence it once had.
In essence, we're likely to see two VERY confident teams battle eachother in the finals. As a Celtics fan, in enduring what has quite possibly been the most difficult and dissapointing regular season (at least with our previously-held expectations) in recent memory, I think this Celtics team has turned around against ALL odds and done the impossible. They've got balls of steel and catastrophically high amounts of resolve. The've already hastened the vacation plans of Dwyane Wade and Lebron James. The same will be done for Dwight Howard and Vince Carter. Kobe is likely next.
If the Celtics were able to handle THOSE superstars, then they surely would not back down to Kobe and crew. They will not lose.