I have been running WM6 on my Dash since the leaked ROM came out. The problem was
that I could not run SlingPlayer on it without doing a workaround. But now there is good news on the horizon.
Sling is actively working on a new version of the SlingPlayer Mobile that will add support for Windows Mobile 6 and are currently looking for people to participate in a private beta of the new Windows Mobile 6 compatible version of the SlingPlayer. If you would like to help us out and try out the new software, send us an email. We will get back to you within 24 hours.
The official release of SlingPlayer Mobile for Windows Smartphone and Pocket PC with support for Windows Mobile 6 Professional and Standard editions will be available in the first part of June.
You can sign up for the beta here