The APs - more
You'll note from the table that products based on Broadcom and Atheros chipsets are equally represented, but that there aren't any products based on Agere Systems, Conexant PRISM, TI, Marvell, Inprocomm, Realtek, RaLink or any other wireless chipsets.This wasn't an intentional snub to any of these companies, but just the way things worked out.
You'll also note that where you find Broadcom wireless chipsets, you also find their processors powering the APs, while the APs with Atheros chipsets use either Motorola PowerPC or Renasas processors.
So that you can see how (dis)similar the designs are, I've included board pictures for your perusal below.
Figure 2: ASUS WL300g board
Figure 3: Buffalo Tech WLA-G54C board
Figure 4: Gigabyte GN-A17GU board
Figure 5: SMC2552W-G and 3Com 3CRWE725075A board
Yes, that's right, the SMC and 3Com products are twins on the inside (sourced from SMC's parent Accton) but with different plastic shells on the outside.
Figure 6: Linksys WAP54G V2 board
Also worthy of note is that I tested the currently shipping Linksys WAP54G (the V2) shown in Figure 6 and not the original design shown in Figure 7. You can see that the V2 is a very different cost-reduced animal using Broadcom's less-expensive 4712 AP-on-a-chip and sporting the smallest amount of RAM (4Mwords) of any of the products tested.