It may look like MSI's X-Slim X600, but this is actually the company's unannounced X-Slim X610. Ostensibly the same as its early cousin, the X610 differs in switching from Intel's Core 2 Solo SU3500 processor to AMD's 1.6GHz Athlon MV-40 CPU. According to Russian site 3DNews' review, this cheaper processor will hopefully bring down the whole cost of the X610.
That's pretty important, because they also found that both battery life and performance suffered as a result of the CPU change. The latter shouldn't have too much impact, they claim, but the former could end up a real issue: under heavy load the X610 managed less than two hours runtime, which doesn't bode well for everyday longevity.
Still, you're getting the same 15.6-inch display, ATI Mobility Radeon HD 4330 graphics, 250GB hard-drive and 4GB of RAM, the same specs (GPU particularly) that set the X600 up so well at video processing and the like. It all hinges on how much MSI decide to charge for the X-Slim X610; the X600 comes in at $799, so undercut that significantly and they may find some buyers.