If you're using SharePoint, the new version is just fantastic and redefines many concepts in SharePoint (workflow, blogs, wikis, Office integration, administration, backup/restore, IIS and SQL Server integration etc) (http://www.microsoft.com/sharepoint/default.mspx), the new SharePoint Designer (http://office.microsoft.com/en-us/sharepointdesigner/FX100487631033.aspx) used as a replacement to FrontPage also is great and is fully integrated to SharePoint.

If you're not interested in SharePoint, the new Office file formats (http://technet2.microsoft.com/Office/en-us/library/42a75e09-a6e1-4c0f-b77a-dcfa5b6f11c51033.mspx?mfr=true) are also very interesting. There is an utility for converting old Office 2003 to the new Office 2007 files: http://technet2.microsoft.com/Office/en-us/library/42a75e09-a6e1-4c0f-b77a-dcfa5b6f11c51033.mspx?mfr=true.

The context tabbing also helps a lot navigation.

Those are just a few things that impressed me.

I plan to use them all as soon as I receive my production copies, even taking any risks of instability or bugs (have been testing the betas and for my use they are quite good, just SharePoint V3 has some issues that I hope will be addressed in the final release).

Microsoft did a great job, IMO, and think it's worth a check.

Hope it helps.

>Give me some hints about it's worthiness, please. As you can see by the rest of the comments, everyone else who commented is holding off.
>
>>Absolutely worth it. I've been using it since Beta 1 and really love it, especially Outlook. I'm just waiting to get the disks before installing because I don't want to download it.
>>
>>>What's the word on the street about Off. 2007? I have an MSDN sub, so it would be free to upgrade. Is it worth it?