I'd bank that the grips will add a static amount of TP per hit, to make it easier for a GA or any 2H wielder to hit 100% in the same amount of time as a DWer.
The only picture they show of one shows it lowering the delay which I'm assuming is going to lower your TP per hit like everything non-Haste since the TP adjustment update. Wonder how much it's going to affect sam's who use 6hit gear builds.