Sling Media revealed a pretty enticing update to their SlingPlayer app—namely, it will be updated (and upgraded) for the iPad...eventually.
Aside from pursuing a future including both H.264 and Silverlight support (as opposed to crumby old WMV) for Apple and Windows Phone 7 platforms, the company is planning on increasing streaming resolution beyond 320×240 for at least one particular device. From Sling Media:
When it makes a noticeable difference in quality, we will definitely provide higher resolution streaming. The iPad is a good example of a device where we are hard at work on this, but unfortunately it won't be there at the April launch.