With no surprise, Asus is still leading the mainboard market. However, the proportion tends to decrease this last year. Since 2006, Asus is actually concentrating on his laptop PCs more than on the desktop mainboards. That profits to Gigabyte, #2 with 20% of the mainboards, that leaves the other competitors far behind. MSI is #3 with 8%, due to a lack of efforts on the retail sales (boxed products)(MSI concentrates on OEM). abit is #4 (not much present in Europe), and DFI #5 (the DFI mainboards are targeted to power users).
80% of that chipset market belongs to Intel. This is not a surprise since Intel chipsets mix quality and performance. NVIDIA is #2 with 10%. Quality explains that position, but also does the exclusive compatibility with SLI. In the entry level, VIA and SiS parts are decreasing. Last but not least, ATI chipsets represent 2% of the total.
On AMD platform, NVIDIA is the leader, and the nForce are indeed very popular toward AMD CPUs users. However, ATI part is increasing, especially since the brand was bought by AMD : from 6% one year ago to 16% now. VIA used to be well placed, but is now below ATI with 12%. Finally, SiS decreased and is now at 3%.