How different is coding for MS Office 2007 vs MS Office 2003?

[ggunter]

My company will be upgrading from Microsoft Office 2003 to Microsoft Office 2007 in the near future and all our processes will need to be rebuilt.

I expect to be asked for an estimated completion date but I have no idea how different the coding will be. We currently have automation built that accesses Access, Excel, and Word. Is this a major re-write or are we just talking about changing some connection strings?

I've Googled it but I'm not finding very much that's helpful.

Any feedback would be helpful. Thanks!!