Yup, the Messy Marv appears to be a greatest hits comp.
From what I saw (by enlarging the pics), the JT one is another "Collector's Pack." It has Daz and JT's two albums from 2001 (LONG BEACH 2 FILLMOE and GAME 4 SALE), the BLOCK SHIT CD from Yukmouth and The Gamblaz (also 2001) and GOTTA GET IT (JT and Juvenile) from last year.
As for the JT/Young Noble one...my guess is that it must be the new collab CD that JT talked about back in June. Maybe Northern-Ridaz.com will eventually post it up, since the Rapbay site doesn't appear to have tracklistings...
PEACE!
