Yes, it is rather sad for a pilot to write down these particular weak spots but I'm rather frustrated with the results of the latest beta build.
Some things you can't do (some are still broken) are:
-Voice and video chat with other Google Talk members through Gmail and Google Talk app
The whole point of having this app on here and Google Talk on Gmail is for us to have the ability to use our cameras and microphones; considering that I can do neither; this is the biggest flop so far.
-Ability to communicate with Skype users through IMO.IM
This isn't possible right now given the fact that the microphone doesn't work or the audio is way too low. The settings panel however displays no microphone and no camera (even after the Pepper flash plugin has been disabled)
This is another setback for many users because people will want to communicate on Skype as it is one of the biggest VoIP services available to date.
You are still unable to watch WMA, AVI files and HTML, JSON files will NOT delete from the file manager. Integration is poor as the only integration into the file manager currently has shown to be Picasa but if you browse through the Chrome Web Store; you can find a few add-ons to make this a little bit better.
Overall, Chromebook isn't half bad for basic uses but for more advanced uses such as VoIP, Video, and other forms of Audio calling; it currently ranks at the lowest denominator in terms of its offerings and services. BUT this is if you are on the Beta channel still. Stable seems to be generally the same way but slightly better.
Regardless, Google has a huge amount of work ahead before Chromebook will be known as a stable and reliable alternative to Windows and other like systems. I am hoping for Google's success with this but only time can tell. If the basic functions can't be added or panned out to work with Chromebook's (especially for us with Cr-48 computers) - This will be a major failure on Google's behalf.
Here's to hoping!