"Porting the art" is one of the tasks for which Ryzom will welcome developer support. Finishing porting to GNU/Linux is another goal and I'm sure there will be a little more coverage about the game here on Free Gamer and on other blogs once it runs. :)
(4 MB 24x24 preview of about 14000 of 17463)
I think most ground textures I saw were rather small (128x128) but of high quality and also include to-transparency alpha-blend tiles that are helpful for transitions between ground types. There are also in-game icons and GUI elements.
Here are the most popular resolutions, if you're curious:
files resolution
5493 256x256
2243 128x128
1864 256x512
1422 32x32
1337 64x64
1142 512x512
646 24x24
613 128x256
316 40x40
238 64x128
199 256x128
137 1024x1024
121 4x4
116 16x16