We now have had many thousands of PI in the hands of competent enthusiasts for some weeks or even months. Progress on the early bugs and shortfalls has been amazing.
1. SD Cards. The Pi could not read some SD cards (the better ones ironically) - either properly or at all. That seems now solved on new images, even if there was no clear announcement on that feat. Forum indications that it was solved in June did not help the Squeeze users. But the Raspbian distribution "works for me" on the one "problem" SD card I did have.
2. Lack of Floating Point Processor - or at least being able to gain speed from the one that the Pi has built in. Again, the Raspbian version seems to have that solved. Fantastic.
3. Multimedia. I have to consider omxplayer just a proof of concept - it is not a prime-time media player. It has no controls. It overlays the X screen instead of working with it. I terminate it by CTRL-C in its startup terminal ! But that issue is presumably software, and ought be eminently solvable in due course. (I haven't delved into the multimedia specific distributions. I may be unfair.)
4. Power Supply woes. The Pi has no battery, unlike a smartphone or laptop, and no inbuilt regeneration of regulated power voltage. The 5V parts run directly from the power pack voltage. Economical, sure. But as many find, some power packs droop under load to below the magical 4.75 volts. Add to that, the drops in voltage when serving direct-plugged USB devices. And so many are finding that their Pi gets flakey. Even with the simplest USB load (keyboard and mouse), performance can be troublesome. The usual advice is: Get a stiffer power supply, and use a quality powered USB hub. This power supply advice may be sound as far as it goes - the Pi is weak here.
BUT 5. - The power supply advice is forming a smokescreen across the biggest Pi issue. The USB system is broken. Too much load (for the power supplied) and keyboards go erratic, mouses stop, network stops. Hotplug a device - even a simple flash stick - other devices drop out. Plug in a device for which there are no working drivers, and the Pi chokes until it's pulled out. Put a traffic load on a network (eth0, or a 3G stick if you are lucky to get it connected), and the device drops back out.
On my laptop, the worst I can do is mess a file by pulling a stick before unmounting/ejecting, or I can curse an unsupported device whose maker only made install disks for windows. BUT MY LAPTOP KEEPS WORKING. The Pi doesn't.
As I said, the Pi is currently being worked over by a crowd of skilled techno-people, all keen for it to succeed, all willing enough to forgive for now. But the target market is the kids. Today's kids were born with USB cables for umbilical cords. Their first uttered words were "rightclick" and "online". Much as we would like to wean them from the consumer mentality where everything should (for $) just work, they still do have expectations that stuff should "just work". The days when my static ram chips would change their bit data at random occasionally, the days the TRS80 (1) expansion box had flakey connectors that caused reboots, we worked through it - there was nothing better yet. These kids won't accept a Pi that just doesn't work right.
Besides the often heard complaints on USB in the forums, the USB issue has had several quite technical threads. See for example
https://github.com/raspberrypi/firmware/issues/9
and
https://github.com/raspberrypi/firmware/issues/19
Now those threads seem quiet.
The elephant is still in the room.