Hope you don't mind some constructive criticism:
I love it! the buttons in the debugger control window (e.g. Step In, Step Over) sometimes don't pick up mouse clicks after flicking through the debug tree so have to be clicked twice in order to step through the code
That's a known issue, I'm fixing it for final release.
it seems like the entire debug tree is recreated after every step, which looks unsightly when it flashes but also, means that the treeview is not scrolled back to the exact same place everytime
Yes that's true, not sure how to fix this as even using the updating tree flags on VS, it seems it produces flickering... I'm looking a little bit more on this. Also to the Tree scrolling issue.
The new icon... Not sure if I really like it. I was adding new icons to support the new Vista ICO format. I supose (hope) I'll make something better for the final release.