The first thing most users will notice when upgrading to Windows 7 is that the Sidebar is no longer present and has instead be replaced by dockable areas on all edges of the screen. The only downside to this is it means gadget's wont automatically re-sort themselves if one is removed or one changes height which can be annoying. This also means that gadgets don't detect when they've been removed from the dock area, therefore all gadgets are in their docked state by default. There's now a little icon which you can click to make the gadget increase in size to its undocked state.

Currently as far as Gadgets go, there's not many improvements, memory management has been improved and some of the 50+ long list of bugs have been fixed, but I've found two that have been introduced (and possibly now fixed in a later build).

For the developers:

The first is that if you have a tag and you don't set the width or height then it won't be seen. In Vista there was a default width and height of 100% but this is not the case in Windows 7 so many gadgets which left that out may be missing a background or have some sort of pink fringing.

The second is that if you set the charset of a gadget in a meta tag in the HTML this will break the gadget. Yep, if you put a tag in that does nothing, it will break the gadget. Even weirder is that if you put in an invalid character set, say ‘blah' then it won't break. So it's actually checking if you defined a valid character set and then breaking. And by break, I mean the code will error and not continue so the gadget won't load properly.

And for the users:

I've submitted both these bugs and both have been marked as fixed so we'll see what happens in later builds. For me the only important gadget this broke was the National Rail gadget, I've emailed the dev and they've forwarded a fixed version to national rail I believe so we'll have to wit and see if they update it or Msoft fixes this issue. It's an easy fix but I can't post it here without getting in trouble.

One area that could be promising is the new Sensor API. The weather gadget has been updated to support location sensors so it's possible other gadgets might be able to access sensor data so like an ebay gadget could only show listings within a certain range of your current location.

Overall there's not much change which is a shame as there's a lot of little things that could have made a big different like flyouts that stay open for example, or larger settings pages.