If by "anime elements," you mean per encounter or per day abilities that actually make sword-swinging more interesting, then yes, I think D&D could use more of this. The classes in Bo9S actually make warriors in light or medium armor that move quickly about the battlefield viable characters, as opposed to every fighter having to be in big heavy armor and wielding as big a weapon as possible.
Here, again, is choice. In 3E, if I want to make a lightly armored fighter with a rapier or other light weapon, I'm not helping the party unless there is a "tank" as well, and that may mean not having another core character in the group. I'm going to get hit a lot, need more healing, not do much damage, and ultimately not protect the "weaker" party members. Now, with Bo9S, the powers that my swordsage or warblade wields can do a lot of damage with pretty much any weapon I choose to use, as well as make my AC high enough to be viable (and this is in light or medium armor). Or, play a crusader with Devoted Spirit or White Raven schools: you can heal yourself and your party as well as give them other benefits in battle.
In short: you can make any melee character you want, and they can DO SOMETHING other than swing a sword and do damage. This makes them much more interesting and useful. If 4E brings this to all classes (which it sounds like it does, and it really wouldn't take much to apply Bo9S schools to core classes), then bring on 4E!
