SharePoint designer 2010 has changed quite a bit from its predecessor – certainly on the UI side. In other ways it has remained the same (its occasional inability to tell whether or not a file is checked out is still very annoyingly persistent). One of the major changes was how it handles .aspx page editing.
Previously SPD2007 had the concept of advanced editing, and a more locked down standard editing environment. This was controlled BY aven’t been able to find an application option to change the behaviour of the “Edit file” link on the information screen. If you’re working on a web site, the advanced mode results in an awful lot of extra clicking, and an awful lot of cursing after being presented with yellow highlights.
If there’s something that I’m missing here, please feel free to fill me in!