Tokens need to be stored somewhere (local/session storage or cookies)
Tokens can expire like cookies, but you have more control
Local/session storage won't work across domains, use a marker cookie
Preflight requests will be sent on each CORS request
When you need to stream something, use the token to get a signed request
It's easier to deal with XSS than XSRF
The token gets sent on every request, watch out its size
If you store confidential info, encrypt the token
JSON Web Tokens can be used in OAuth
Tokens are not silver bullets, think about your authorization use cases carefully
http://blog.auth0.com/2014/01/27/ten-things-you-should-know-about-tokens-and-cookies/
http://blog.auth0.com/2014/01/07/angularjs-authentication-with-cookies-vs-token/