I'm getting my head round this SQLX at the mo! It's going to be good, there is an article in this months VSJ.
Could you imagine putting <WebMethod> infront of your store procedure 'create procedure' statement to turn the thing into a XML Web Service ... now that would be cool!
As for Yukon, sounds great, would kind of like to see 'partioning' and 'material views' to a la Oracle. Would be cooler as well if you didn't have to pay extra for it ... a la Oracle!
What I would most like to see out of Yukom is performance. I would love to see this database be a real speed demon!