Martin, are those actual screenshots, or something you created? If they are actual shots, I have a couple of issues:
1.) I don't mind that the national current conditions bar on the left is still shown, but, since the radar on the bottom left corner is hidden by the local LDL, the "radar" label should be either removed or repositioned on the national feed so that it's no longer indicating a radar that's hidden to those now seeing a local LDL.
2.) Why is the Intellistar HD using the pre-2010 weather icons? That creates a discontinuity with all of the other weather icons shown on The Weather Channel. And, personally, I greatly prefer the newest set of icons. The older ones do look more realistic, but the newer ones remove confusion. For example, I had a hard time telling the difference between rain (white streaks against a grey background) and snow (white dots against a grey background).
3.) The banner underneath the city name is a little confusing. For example, "The Week Ahead" shows current conditions, "Tomorrow" shows the forecast for the upcoming week, etc. It's not a problem to show what's coming next, but that should be clearly differentiated from what's currently being shown.
4.) On the current conditions display, the data covers up the labels ("visibility," for example).
5.) On the week ahead display, the day labels and the colored banners underneath them don't quite match, and the result looks very sloppy.
6.) Where's the clock on the small LDL?
Other than that (whew!), the idea seems to be quite good, and I look forward to the Intellistar HD being deployed in my area... hopefully with a bit more tweaking.