I got a prompt this morning asking if I wanted SP1- Office 2007

If it was ANY news on Vista, there would be 30 comments at least. I guess office 2007 is not such a sensitive area. People can still use office 2003 and not give up an "DX10" benefit or similar. And, for those who want to use office 2007, just remind them to save as .doc instead of .docx or keep them happy and install the update for office XP/2003 for .docx formats. By the way, does anybody know any useful difference between the old and new formats? Or is this just a way to keep StarOffice and similars away.

The only thing I've see is the much smaller size of files. But I'm not such a specialist to try find other differences :)

You really haven't been paying attention, have you?
The new formats are zip files (try it - change the extension to zip and look inside).
They contain everything about the document in xml files and other content files, in a logically laid-out structure.

It's a giant leap ahead of the partially binary/partially xml document formats of the past.
Because they are zip files, your average document is significantly smaller.
Also, because they are zip files, they are easily accessible WITHOUT using the office Primary Interop Assemblies, which is a boon for developers wanting to roll their own interfaces to the document formats.
The xml format, for the contained xml files, is also published and easily accessible.
In addition, the new format allows for a much easier way to embed additional resources, such as fonts, images, audio, or any other content that previously had to be interwoven into the doc file or stored in a predictable location and accessed via a hyperlink.

StarOffice and OpenOffice certainly can read the new Office formats, if they really want to. All it takes is getting over their religious issues and parsing a little bit of XML.

So, in short, yes the new format is useful, and it alone is worth the upgrade, IMO.
The new UI is ridiculously easy to use, too, and far easier to learn for a novice user.

Excel is so much better in 2007 than any previous version that it's just not fair. It now includes intellisense for formulas, real-time updates to formatting before you even apply it (basically an automatic real-time preview), table formatting that is simple and intelligent (with awesome features like filtering and per-table sorting, grouping, and whatnot).
You really do have to try it to believe.

We bought it just to reduce the size of our central document store, but quickly realized that we got a hell of a lot more than we were expecting.

My hat goes off to MS, on this one.

Thanx Opie