Thanks for the tipp Francois - the ticket is still pretty early stage, so any input is valuable. It will be a big undertaking, with the potential to change a lot of the ways we currently use the ORM. We won't be getting into our own SQL lingo (like Doctrine with DQL), but rather try to provide fluent objectified interfaces for 95% of the tasks you would usually express in SQL.
Feel free to CC yourself into the ticket or comment on there: http://open.silverstripe.com/ticket/2986
For more info on doctrine, in case anybody's interested: http://en.wikipedia.org/wiki/Doctrine_(PHP)