While not shipping just yet, there are plenty of reviews of Google's new Nexus 7 tablet. Most of the reviews I have read complain about the lack of expandable storage options. The Nexus 7 does not have a MicroSD slot, nor does its USB port support mass storage devices.
At first I was definitely agreeing with the reviewers. If you install a few of the bigger games onto the tablet, there really won't be much room left for high quality videos to take with me on the road. I travel in the US a lot, so it's not really feasible to depend on cloud services when using a very limited data plan shared from my phone....
Shared from my phone?
That was it. I always have my phone with me (except for when I drop and break it). My phone has a 32GB MicroSD card, and I already have the ability to share my phone's content using Twonky. All that is necessary is to enable the WiFi hotspot (whether I'm connected to cellular data or not), and my phone becomes a portable media server with expandable storage.
Granted, there are some limitations. I'm not sure this is the best solution if flying. I know that some airlines now have on-board WiFi, but I do not know what the policy is with respect to firing up your own hotspot.