From what I've heard there will be three MTB "bags" available come Spring 08. Here's the low-down (if I've said too much mods please delete):
TOOL BOX 3.0 92126 - Looks similiar to the current Tool Box 2.0
DIMENSIONS: 20" H x 12" W x 8" D (1300 cubic inches) / 50.8cm x 30.5cm x 20.3cm (21.7 liters)
Freeride/downhill bike pack holds full-face helmet, hydration reservoir (not included), and body armor/shoes in side pockets. Top lid pocket compression-molded for eyewear/media player and features headphone port. Contoured back panel, phone holster on shoulder strap, organizer for trail essentials,and removable waist strap.
$100
TOOL POUCH 2.0 92127 - Has a similiar shape as the current Tool Pouch but in my opinion the design is quite different with how they integrated the clamshell closure and with the addition of what looks like a small top lid compression-molded pocket.
DIMENSIONS: 16" H x 10" W x 4" D (250 cubic inches) / 40.6cm x 25.4cm x 10.2cm (4 liters)
MOFLOW 100 oz. hydration reservoir features pump system with bite valve, mouthpiece treated with Microban® antimicrobial protection, improved clamshell closure helmet stash panel (stows away when not in use), new mid-body zippered opening, mobile phone holster on shoulder strap, and interior organizer for trail essentials.
$90
TOOL POCKET 92145 - Looks similiar to the current Tool Pouch
DIMENSIONS: 16" H x 10" W x 4" D (250 cubic inches) / 40.6cm x 25.4cm x 10.2cm (4 liters)
Lightweight trail pack pared down for the essentials: water, tools, cell phone, extra layer. Hydration system with antimicrobial, 70-oz. reservoir. Internal organizer, plus under-flap pockets and key clip. Removable waistbelt for comfort and convenience.
$55
All three will be available in 001-Black and 323-New Khaki