...you're ignoring high-end gaming market
The problem is the high-end gaming market is not large enough to offset the cost of deliverying and supporting (already being impacted) the product. If you consider what is the "extra" that even the Audigy offered over some of the latest on-board chipsets, it's not much. It may have a few aural tricks that it can do but how much is that really worth? And, if you read any of the performance analysis, the newer onboard chipsets do not significantly degrade performance anymore than a discrete card. Don't get me wrong, I am not slamming Audigy or Audigy2.
The real question in a situation like this is does the add-on product offer enough value to justify the additional expense (and trouble of customization) over the standard feature set? I believe Creative recognizes this and trys to build value by the SW that is included with the retail cards and features (firewire ports...now what does that have to do with sound). However, at $130 for the Audigy2, I think it will be a tough sell. Once the newness wears off, I think you will see some very large rebates being offered.
But even with lower prices, the whole sound card market is going to be squeezed hard. The one market segment that Creative may be able to hold onto for awhile are the users wanting separate break-out capabilities found in the Platinum series but, again, that is a small market. Even that is threatened because case manufacturers are starting to build some of these features into their designs. When mobo manufacturers start to include this as standard, and it is only a matter of time, there won't be any market left except for specific niche applications.