Paul Thurrott is reporting that Windows Phone 7 is getting its first update as soon as February (it might even be RTM this week). Codenamed NoDo, for 'No Donuts' (anti-Android?), the first update will bring copy & paste, a bunch of software fixes, support for Qualcomm 7x30 chipset and a CDMA location stack.
A major update, codenamed Mango, is also in the works. This will supposedly bring Internet Explorer 9 with the Trident 5 rendering engine, HTML 5 and Silverlight, gesture support and other entertainment functionality. Thurrott says this could possibly be Windows Phone 7.5 but notes that it currently calls itself 7.2. There's no leaked timeline for this update yet. [Windows Phone Secrets]