Some useful Movabletype plugins have been updated, StyleCatcher, which shipped with MT3.2 has been updated. Note that you can edit the MT templates, I have, but be careful not to change the functionality of the default classes or stylecatcher will not work for you. I changed all my templates to point at a second stylesheet, which gives my own "tweaks". This lets me change the background style with impunity... why is it that most of the styles in the MT style library are fixed width? For that matter, why is MT itself fixed width? As regular visitors may notice, I've been playing with stylecatcher for a little bit, some things change, and some things stay the same. I'll eventually come back to the green-grass based look as it is 'fluid' and resizes.
In addition, Better Entry Preview has also been updated.
I think MT-Preview does the job better that Better Entry Preview, as it uses the actual templates the article will be published with, but betterentrypreview is better than the regular preview, so it does what it says on the tin!
The downside with mt-preview [nb: instructions outdated, see above link] is that the installation is a touch tricky, though with care (and making backup copies) it doesn't take long. Better Entry Preview, on the other hand, looks easier to install, but to will require extra CSS fiddling to get the preview looking like your site.
Download your plugin and take your choice.