While Matt Mason has been blogging away furiously at the Revit 2010 platform/API enhancements, I've got a smaller feature to talk about.
If you're anything like me, you would have run into the situation where you create an external command, link it up in the ini file, and go to run it.. and get nothing, no error, no warnings, just nothing. While the journal file can sometimes offer a little bit of assistance, you really have very little to go on.
This has changed in 2010, with increased reporting of errors in API commands. One I noticed today is that if you link to a DLL file in the revit.ini that doesn't exist, you will get a popup warning alerting you that your dll doesn't exist and thus the command has been disabled. This is great, as often typos are made in the revit.ini, and this points you straight to it.
Another one is that when an unhandled exception occurs, a friendlier dialog box is now shown, alerting the user to the error, and allows them to view technical detail if they wish. Previously it was a standard .net dialog box which didn't mean much to the end user.
It's the little things that count, and this little thing is a worthy inclusion in Revit 2010!