Hi Arvind,
Well, what they say is true (or, no reason to believe it is not true), but it anticipates upon no other ways to achieve what they claim is to be achieved (which latter again by itself is correct). So, it tells you that there is no other means to use ASIO over USB (except for ASIO4ALL which is a layer and which is not good or not the best indeed), but there's also
http://www.usb-audio.com/ for ages which just does the same (AFAIK).
Also, as you know, once you are on Vista there is WASAPI (like XXHighEnd/Engine#3), so no need to use it there.
Similarly, on XP there is Kernel Streaming. No need to use it there too (for players supporting KS of course).
The other way around, their "all players can utilise it" is not true, because such a player first must support ASIO. Well, not many will exist that do not, but XXHE at least is one of them.
But ASIO over USB by itself is useful within above context, and sure is not wrong.
Peter