As you develop your linux client, and before you cast the design in stone,
might I humbly suggest a stripped down version of the client that is a simple,
command based background process,
with no screen saver, and no calls to X.
In fact the fancier version, with the graphics, could be built around
the simpler version.
There are three reasons to do this.

1. It's the Linux way - the Unix way - and the right way.

2. Many Linux boxes run as servers, routers, background processors,
work stations, etc, often without desktops.
It's easy to rebuild the kernel and supporting environment to service a
specific task, and unneeded software is often jettisoned.
It would be a shame if your Linux client required software
that is often not installed on the boxes, for various reasons.
A thin client that requires little more than tcp sockets and a file system would be great.

3. Being entirely selfish, two of my three linux boxes don't have X,
or any screen software installed - they don't even have monitors -
because I am blind.
Still, I'd like to run the client when it comes out.
(The third Linux box is for my kids, and has desktop
and games and all that.)

Just a thought from a long time unix programmer.
Thanks for listening.