With the right accessories, the Surface Pro makes a mean alternative to your average laptop -- but even with the second generation model's improved battery life, it doesn't last long outside of the house. Soon, that might be less of an issue: Microsoft is preparing to ship out the tablet's Power Cover keyboard later this month. The $200 Type Cover variant was originally announced with the Surface 2, but didn't make it to market with the new tablets. Now the company has given it a March 19th ship date, promising buyers 70% more battery life for Surface Pro, Surface Pro 2 and RT-based Surface 2 slates. Pricey? A bit, but can you think of a better way to nurse your Windows 8 slate on an international flight?