Naturally, Chrome's mounting presence has affected Internet Explorer and Firefox. IE's descent continued in 2010, dropping from 62.12% in January to 57.08% in December, while Firefox fell from 24.43% to 22.81%. Both Microsoft and Mozilla are preparing significant updates for their products with Internet Explorer 9 and Firefox 4 due sometime early this year, so it'll be interesting to see how that affects the stats -- if at all.
Browsers aside, Net Applications shows that Windows 7 gained more than 13% during 2010, closing the year out with 20.87% of the operating system market. That's one in five computers, mind you. Windows XP is slowly losing footing, falling some 10% to 56.72% during the year. Meanwhile, Vista dropped more than 5% to 12.11%. Mac OS X 10.6 and 10.5 collectively represent 4.51% (1.45 and 3.05%) as of December.