Rule of thumb: Taclord sets up attacks. Bravelord gives attacks.
Mind explaining that a bit more for the 4E noobs?
Oh! Oh! Seconded!
The Tactical Presence feature gives allies an unnamed bonus on attacks when they spend an action point, whereas the Bravura Presence feature instead grants a melee or ranged basic attack. That would be the basics. Powers that key off Intelligence and those that have an extra effect for Taclords often give a bonus on attack rolls, damage rolls, or similar.
The Taclord can set up nova turns by giving allies big bonuses to hit and damage, and is thus the Ranger's best friend, whereas the Bravelord can enable nova turns by giving his allies extra attacks, and is thus the Avenger's best friend. Taclords are, however, also suited to giving allies extra attacks (with Commander's Strike).
Of special note is that Bravelords do not, fundamentally, have to be Cha-based, as their feature is the only one that is not keyed off a stat. Also of note: Harlequin Style, from Dragon 372, gives the warlord a bonus to defenses equal to his charisma mod against the attack he takes from Brash Assault.
I'd link you guys to a Warlord handbook, which can probably explain the issue better than me, but the wizards boards are currently down.