-write to the filesystem. Applications must use the App Engine datastore for storing persistent data. Reading from the filesystem is allowed, and all application files uploaded with the application are available.
-open a socket or access another host directly. An application can use the App Engine URL fetch service to make HTTP and HTTPS requests to other hosts on ports 80 and 443, respectively.
GvR mentioned today at Google I/O that the Go runtime was championed by another group within Google. Apparently, the same thing happened with the Java runtime before it was brought into the App Engine team. He expected the same thing to happen with the Go runtime. So one would expect new features to come to the Go runtime slightly after the other "first class" runtimes (Python and Java).
yeah, app engine is pretty limited in that regard. that's why my current go webapp (which needs to send sms and IM) won't run on the app engine. ec2 ahoi ...
So you won't be able to run a process like Doozer that communicates with other ports/protocols.
EDIT: More details from the docs at http://code.google.com/appengine/docs/go/runtime.html
An App Engine application cannot:
-write to the filesystem. Applications must use the App Engine datastore for storing persistent data. Reading from the filesystem is allowed, and all application files uploaded with the application are available.
-open a socket or access another host directly. An application can use the App Engine URL fetch service to make HTTP and HTTPS requests to other hosts on ports 80 and 443, respectively.