No info on price yet, but it's going to be splitfire like some of the RAP-4 guns.
Normal Spyder layout inside, though this one, like all Kingman's 2012 guns, has the Eko valve.
2012 Spyder MRX Paintball Gun - BlackKingman originally claimed the Eko valve would yield 1800 shots from a 20oz fill, but has now lowered that claim to 1500. Independent testing shows the actual number to be around 1650.
Magazine holds only 11 rounds. No word yet on whether it's first strike enabled.

Kingman has also announced another gun called the MR100 which will replace the MR1. Price is $100, and there are no pictures yet but it sounds as though it will be the same gun as the MR1 but Eko-valved and with picatinny rails on the side.
2012 Spyder MR100 Paintball Gun - Black - MCB
Looks like Spyder is getting into the magazine market.