There is no huge change between 2007 and 2010, but it seems to be more streamlined. I've only fully used Excel and Word as I mostly do not have a need to use the other programs but it seems to be generally faster and slightly easier to use than 2007. The ribbon is still there at the top but it can be removed, "file" is back at the top but this shows the same options as the old 'office button' in the top left of 2007 (which is now gone)
Overall, a good update to a much used software. If you're running 2003 then i'd recommend you upgrade. But, if you're already running 2007, then this may not be entirely required as it seems to mostly be the same.