In the course of doing some research for a client just now, I found some very welcome news. On March 6, Microsoft released a Microsoft Office Compatibility Pack for Word, Excel, and PowerPoint 2007 File Formats. It allows you to open, edit, and save documents, workbooks, and presentations in the (far superior in my experience) file formats new to Microsoft Office Word, Excel, and PowerPoint 2007.
I've been using Microsoft Office 2007 Pro since I bought it last summer and I could never go back. I'm not going to write a full review here as there are plenty of those out there, but besides the vast usability improvements, the file sizes are typically at least fifty percent smaller than previous versions. That adds up to a lot of disk space saved and also makes files much easier to transfer and e-mail. I point that out because that's a gain that can be had by using this free compatibility pack.
I use Excel a great deal and some of the improvements there are huge. Typically I'd prefer to send you to a 3rd party review, but Microsoft actually sums up the key improvements accurately here:
