Along with the Warren I too have just joined the Blog team at Umbraco.org. I began working with Umbraco in July 2007 after becoming dissatisfied with DNN for my intended use. I think what did it for me was the 7-part screencast (almost 3-hours!) covering how to create a custom control for DNN. With Umbraco this can be accomplished in a matter of minutes using ASP.NET user controls or XSLT.
In December 2007 I attended Niels’ Level-2 course in Copenhagen (which I highly recommend) and I’ve been an enthusiastic Umbraco devotee ever since.
I run the Umbraco focused company Motus Connect and am the Technical Lead for The Homax Group. I am also the current project owner of the Commerce for Umbraco open-source project. This project, although quite preliminary at the moment, will add commerce capability to Umbraco.
Finally, I am a member of the Umbraco marketplace team creating the repository for all things Umbraco (for purchase) and accessible alongside the existing Umbraco package repository.