Talk about mixed signals from MS. First it's VSTO is the future, then VSTA...there's that lovely video on their site mocking "Mr. VBA guy" (I don't have the link, it's somewhere on the Methods in Excel blog which you should be checking out anyway)...now this press release:
"The Mac BU also announced it is bringing VBA-language support back to
the next version of Office for Mac. Sharing information with customers
as early as possible continues to be a priority for the Mac BU to allow
customers to plan for their software needs.2 Although the Mac BU
increased support in Office 2008 with alternate scripting tools such as
Automator and AppleScript — and also worked with MacTech Magazine to
create a reference guide, available at
http://www.mactech.com/vba-transition-guide — the team recognizes that
VBA-language support is important to a select group of customers who
rely on sharing macros across platforms. The Mac BU is always working
to meet customers' needs and already is hard at work on the next
version of Office for Mac."
http://gizmodo.com/389845/office-for-mac-2008-service-pack-1-out-today-visual-basic-coming-back-to-macs
There's no consistent stance to be found from these guys. Personally, I think I'm just going to ride out the VSTO/A phase by ignoring it, much like I ignored that odd scripting thing in Office 2003 that you could get to by hitting Alt+Shift+F11.