According to the latest reports Service Pack 1 for Windows 7 to be ready in the summer of 2010.

Since the release of the RTM version has passed a lot of time because Microsoft is not idle, and working on the first Service Pack. According to the Russian site Wzor.net already in January 2010 we expect a first beta of SP1. Successively issued three versions will have previews. The final edition is expected in summer 2010. It is worth noting that the information served by Wzor.net are usually accurate so you can expect that publishing the plan submitted is true.

The sooner Microsoft finishes work on Service Pack 1 for Windows 7, the better. It is known that a large number of customers (especially business) with a change to a new system of waiting until the release of the first set of the update rollup.