Now that Avalon and Indigo are available to XP users what is going to make Longhorn better from a UX (User Experience) standpoint? How about starting with something we use everyday? Explorer.
Explorer is used by everyone from developers to grandparents. I'd like to see explorer evolve.
Give us ways to navigate, search and grok what going on, on my hard drives, external drives, camera storage and mp3 players.
Give me time-line views with sparkline bar graphs to show me the number of files by date at a glance.
Give me treemaps so I can see where big files are hiding and let me filter those maps.
Give me search with context, not a serial web page where I click through endless web pages to find something. (Yes, I don't care for Google desktop search. Google's great for the web, however it's not great for my desktop.)
Give me new navigation interfaces. How about a compass rocker style button? Very doable in XAML and Avalon.
Give me some new views. How about stacks of related files when moused over I get a nice preview of the file and some info? (I've got the sketch for this in my Moleskine.) How about graphs of related files? Or stripes of files in a time-line?
Here's the chance for Microsoft to make Longhorn more than a service pack, by leveraging Avalon.