Not being connected with Dremel myself
I can also recommend the latest Dremel Lithium-Ion. Not being nicad or nimh means it stays charged up while it sits in the toolbox and it's ready to go when you need it.
Used to always have a corded Dremel in my work toolbox in case it was needed as every cordless one I'd tried was nowhere near powerful enough, left it at home one day and picked up the Li-Ion one as I needed to use one. The corded one never comes with me any more.