From theflyonthewall.com: XM Satellite Radio channel checks showing MyFi demand huge.

Sales for XM are strongest in Wal-Mart and while MyFi hasn't been widely available it can be seen that this could become the best-selling satellite radio product when supply evens out with demand in 2005.

Considering the timing of the MyFi release, this is pretty much expected but it's good to hear that there's a market for portable satellite radio receivers - even at the relatively high price point.