Pricing for similar hardware has literally crashed in the time it's taken Pi production levels to ramp up. There are now multiple ARM vendors with open source BSPs supporting hardware that's much more powerful and with comparable pricing. See for example http://www.cnx-software.com/tag/amlogic/ and http://www.cnx-software.com/tag/freescale/ .
Unlike the Pi these offerings usually come with Bluetooth, WiFi, larger flash and 1GB RAM in dual or quad core configurations, and pre-packaged in consumer friendly boxes ready for hooking to a display, although access to auxiliary IO buses may be more difficult. SATA (Mele A1000G), GigE (Wandboard) and mini PCI designs (i.mx6 Sabre Lite) are even available.
Price and features aside, don't forget that RaspberryPi is a charity on a mission, so if you can support them with a purchase, please do!
"We don’t claim to have all the answers. We don’t think that the Raspberry Pi is a fix to all of the world’s computing issues; we do believe that we can be a catalyst. We want to see cheap, accessible, programmable computers everywhere; we actively encourage other companies to clone what we’re doing. We want to break the paradigm where without spending hundreds of pounds on a PC, families can’t use the internet. We want owning a truly personal computer to be normal for children."
If all you want is USB, there are (seemingly hundreds of) Allwinner sticks available via Aliexpress, e.g. http://goo.gl/th1bO as low as $34, which is supported via the linux-sunxi port. Boards generally cost more, I've less information on that.
A board like the Pi is defined by these attributes (order irrelevant):
Price
Performance
Exposed I/O
Device Size
Community Size
I don't know of any board that beats the Pi on more than 3 of these attributes.
The allwinner sticks you mentioned are comparably priced, but have a smaller development community and very limited I/O. If all you want is a little media player, I think they are a good choice though.
I'd disagree that the order of those is irrelevant. Far and away the two most important ones are `Price' and `Community Size'. If it cost three times as much, the RPi wouldn't have been such a hit; if the community of users was tiny, it wouldn't matter how cheap it was because it wouldn't have critical mass. The Raspberry Pi managed to get out cheap enough and with enough support to make it a runaway success, which is why we now face a glut of similar machines.
I have an R-Pi and an mk802. I run linux on both. While the mk802 is faster for most general things (compiling, serving web pages, etc) the R-Pi beats it as a media player due to the fact the mk802 video drivers haven't been released.
I believe most people would like a cheap and small board to use it like they would use a regular computer: high-level development, media player, various "apps", small home server. Clearly, for these people, performance/price is the first and foremost criterion. If it works like it's supposed to, it's a done deal.
As for lower level development, you are probably right, few boards can claim to beat the Pi.
The stick you link to is A10s, I'm not sure it's well support by sunxi-linux at the moment. For Linux support, better stick to A10 dongles which cost about the same.
Unlike the Pi these offerings usually come with Bluetooth, WiFi, larger flash and 1GB RAM in dual or quad core configurations, and pre-packaged in consumer friendly boxes ready for hooking to a display, although access to auxiliary IO buses may be more difficult. SATA (Mele A1000G), GigE (Wandboard) and mini PCI designs (i.mx6 Sabre Lite) are even available.