Along with the launch of the Cartel Market, coming out in Patch 1.5, Bioware have introduced some new features to the character preview screen. The first change is the ability to turn your weapon on and off. Using the center button highlighted in the image below will enable your character preview interface to equip or unequip a weapon. (Note: There seems to be a brightness issue with the preview screens that are on the test server at the moment. I'm sure this will be fixed before Patch 1.5 is released.)
Using your mouse wheel while your preview screen is open will zoom in and out on your character, giving you a high res look at all your equipment.
If you're fussy like me, the look of your lightsaber hilt is important, and so this new feature will be a pleasant distraction of your first visit to SWTOR once the patch comes out (in the next couple of weeks).
Apat from being able to preview weapons that you're not able to use normally, you can also preview color crystal effects on lightsabers even when you don't own them. Hit Control and then right click on a crystal to preview how it looks in your hot little hand. Note: You will have to have a lightsaber equipped, or be previewing a lightsaber hilt to experiment with crystal colors.
You can also preview your companion's customizations and weapon options, up close and personal with a rotate feature, which is a massive upgrade to the current preview screen.
I adjusted the brightness in this screenshot to show you the detail you can see when you zoom in.