The problem is not unique to Cisco / Linksys. What you are mainly seeing is a combination of manufacturers' reluctance to discontinue old product and inventory glut.
I asked Cisco to explain their product line recently while working on the WRT120N stories, and in particular, to explain the difference between the WRT120N and WRT110.
They shared a one page slide of their consumer wireless product lineup, that unfortunately I can't post. But it has only the WRT54G2 as a G router, with all other products as N routers.
If you're a regular reader, you know my feelings about products using single-stream N technology. Simply put, I see no need for it on the router side. Single-stream does have a use on the client side, especially for low data-rate devices like printers, smart phones, cameras, etc.
I think this the push is coming from the chipmakers, who would like to phase out production of older b/g chipsets to streamline operations and trim costs.
As for consumer wireless marketing in general, it will continue to use a throw-it-against-the-wall-and-see-what-sticks approach. In the end, there are four basic product types:
- 11 b/g
- Single band draft 11n
- Dual-band, single radio draft 11n
- Dual-band, dual radio (simultaneous)
You need to decide which of these meet your needs, then look for products within each category. Discount any claims for performance that manufacturers make, since there are too many variables involved.