wpml is a wonderful plugin that has so many it takes a while to get used to its power.
A new beta version of the multilingual plugin has been published for early adopters who have already switched to 3.0
What I've tested is interesting and allows quick setting of multilingual website
Flag displaying is almost instant thanks to dedicated functions or specific coding as documented here. Urls paths are well preserved and extended with the 2 letter language prefix.
Post translation is well implemented in the admin, each language displays a + button on the columns of the post / page
Posts can share common custom values or images, technique described here
all strings thath use the _e function in templates are translatable in the admin or in a mo file
as of today the wordpress 3.0 menu and custom post types do not work well with wpml but work is ongoing