From the upcoming
Martial Arts:
"You can parry a grab, grapple, slam (including a pounce or flying tackle), or unarmed Acrobatic or Flying Attack with a ready melee weapon as your attacker enters close combat."
-- Dealing with Charging Foes
"If you’re able to retreat out of close combat, however, you get your full Parry plus the usual bonus for retreating."
-- Long Weapons in Close Combat
In short, close combat only limits an armed fighter if he starts out there and cannot leave. If someone closes the gap, he can tag them on the way in. If he's already in close, he can open up the gap and tag his foe. The moral of the story is "Corner the armed guy and go for the clinch, or you're toast."