It supports graceful degradation. 3.1.2 added multi-vector gradients, and subsequent versions fine-tuned the folksonomy algorithms, but if you somehow must use legacy 2.0 software, you can still enjoy 8-direction gradients and tag clouds.
I recommend you upgrade, once you've tried a tag katamari, you just can't go back to tag clouds.
If you saw the crazy shit they're experimenting with in the nightly builds you'd see the future, dude.