I think it's a very interesting question (which can not be answered yet) if Sharepoint 2010 can be really used (not only in theory) as reliable and scalable CMIS-compliant ECM-repository also for high-volume transactional content management. In the past almost no one (beside Microsoft 😉 could imagine that Sharepoint could be also succesful used for mission-critical imaging-applications for example in the financial industry (e.g. loan-processing or claim-processing) with many millions of documents involved. But this could change if Sharepoint 2010 is that good as Microsoft claims. We will see very soon. WeWebU will definitely test the OpenWorkdesk against Sharepoint 2010 as soon as the CMIS-API of Sharepoint is available. If it's working well (what we all expect) then OpenWorkdesk could be a catalyst for Sharepoint also for these kind of composite content applications especially in the financial industry.
But you don't have to wait for Sharepoint if you want to evaluate OpenWorkdesk. You could give Alfresco a try…
🙂 stw (WeWebU CEO)