Chromebooks won't allow software other than what's available on the ever growing Chrome Web Store.
If you use the Chrome browser right now, you can add these apps today -- they'll show up on your home tab. When you eventually buy your Chromebook, all of the apps you've installed will be available immediately, since they're tied to your Google account.
So, if you don't use Web Apps now in Chrome, then your Chromebook will ship with only a few icons on your home tab. Likely Gmail, Calendar, and Docs at the very least. If you do use Web Apps now in Chrome, then your home tab will include the Apps you've installed.. embedded, I suppose. Only if you use the term very, very loosely.
so I can't download mp3s, mp4s and listen or watch offline? How about ebooks?
You can download, watch, listen and read from the SSD while offline. You can also do the same from USB. Chrome has a file manager that allows you full access to your SSD and Chrome has the apps to do the things that you asked.
Thanks for the link, excellent review. My tablet has 8gb ssd and it provides plenty of room for videos when I'm occasionally offline. Of course, android has many more "offline" apps than the chrome app store.
The more I read, it appears a media player should be "embedded" in the OS and play in the browser. Wish there was a list of what the OS can do besides run a browser!
As others said, you can play media off external storage, e.g., microSD card, USB stick, camera or your phone in 'storage' mode. MP3, MP4 and JPEG work; WMA/WMV do not. I don't know if there's a list of currently supported formats somewhere.