eh...not that simple.
Federer's success at net that day was directly related to his baseline play. To this day i havent seen federer hit his fh AND bh AND serve against nadal on clay as well as rome 2006.
Federer was coming behind some wicked approach shots and was forcing the action because his bh was penetrating the court and he was able to use his fh to outmaneuver nadal. His approaches were calculated and were the result of mostly great baseline play.
If federer was chipping and charging the net ala edberg, rafter. Then i would agree that approaching the net in 80s/90s style fashion would be a viable strategy. This match however is NOT a datapoint for this.
The strength of your approach shots is directly related to whether you are able to gain the ascendancy in rallies. Gaining the upper hand against nadal in rallies on CLAY is a very difficult task. I dont think i need to elaborate on why...
There is a reason on why to this day federer was able to produce one match with truly all court play to even have a chance of defeating a very good nadal. It took his absolute best performance on clay against nadal and he still lost. This is not the norm for federer, and i would be hardpressed to believe the norm for any other "all-court" player against nadal given how well federer plays from the baseline.
To the bold part: I spoke of "the strategy" but I was not referring to any particular past style of net play, still less the type of net play that was heavily characterized by chip-and-charge. Perhaps my phrasing seemed to imply something specific, but all I meant was net play -- high numbers of approaches, however that may come about. And I certainly agree with your description of how Federer came in during this match. That's all I meant by net play possibly working today: I don't need it to replicate any particular past style in any way; I'm just talking about net play, in whatever way (or ways) it might be produced today.
Incidentally I don't know that net play, on clay courts, ever was heavily reliant on chip-and-charge. That was a prominent grass-court tactic, but even then, on grass courts, of course, the main way that players came in was behind their own serves.
Generally speaking, at least apart from grass, it's always been the case that players would make approaches when they earned, or somehow got, a superior position over their opponent in a baseline rally. As you say above, "the strength of your approaches is directly related to whether you are able to gain the ascendancy in rallies", and that's always been accepted -- with one prominent exception.
The orthodox SV style was known as the Big Game, and in its most extreme forms it came under criticism. Ellsworth Vines thought that its most orthodox adherents should develop their groundstrokes more, and that they should come in more judiciously rather than simply coming in behind both serves all the time. He felt that in some tennis circles it was merely taken for granted that merely being at the net would put you in a superior position over a baseliner. And his criticisms were spot-on. But I certainly wasn't referring to the kind of injudicious net-rushing criticized by Vines, as a style that could possibly come back today. That would not work today, and as Vines noted, it wasn't even working back then: the best attackers then were those who attacked smartly and who developed good groundstrokes with which to make good approaches.
Now getting back to the question of net play today: that match was probably Federer's best ever on clay. And he had a stellar success rate, 76%. But it's not as if we're talking about how a 76% success rate against Nadal on clay should become the norm for all players. That was Federer's best effort and even he is not going to be reproduce it every day. All the more true for lesser players.
But let's just start with the fact that a 76% success rate is possible against Nadal on clay. Then shouldn't it be possible to see Federer, at least (never mind other players, for now), produce similar rates on other, faster surfaces? I know grass is not what is used to be, but there is still common agreement that it's faster than clay and that Federer has a greater advantage over Nadal than he does on clay. Yet Federer does not have net stats on grass, against Nadal, that equal his Rome stats, much less surpass them.
Why is that? It can't be that his level of play in the Rome match was a level above every match he's played on any surface. It was a very, very high level -- but surely he's had such days on grass or hard court. And those surfaces should be more suitable for him to come forward. So the natural question for me is, what happened? Why do his matches after Rome show lower success rates and even lower numbers of net approaches?
It seems to me that Roche's influence can be a large factor in all this.
Remember, I'm not asking why Federer did not become Edberg; and still less am I claiming that the tour as a whole can start attacking just as much as they did in the 70s or 80s or 90s. I don't know whether that is possible. I'm just saying, once Federer showed he could have a certain level of net success on clay against Nadal, then theoretically on faster surfaces he could have even better numbers. Yet Rome, on clay, seems to have been his high point as far as net play. Why is that?