Is it possible to download artwork (costumes, sprites) from the cloud 2.0 to 1.4 on my computer? My class has a lot of time invested in the cloud version.

Unfortunately, Scratch 2.0 projects are saved in .swf2 format and Scratch 1.4 projects in .swf, meaning that Scratch 1.4 can't read 2.0 projects. It does work, however, the other way around. But an offline editor of Scratch 2.0 is coming this summer.

Click the ‘share to’ button click on download to 1.4 and that might work. Hope it helps.

Bitmap costumes should be downloadable as PNGs, which 1.4 supports, but sprites are completely different, so not for those.

I only know that it'll not work if you use functions of scratch 2.0 that 1.4 not has.