Depending on your needs, Mayura Draw is a very nice and inexpensive alternative. While it doesn't have all the bells and whistles Corel Draw has, it is powerful enough to handle most simple drawing tasks. However, I have found an occasional .wmf file that it won't import properly.
Xara Extreme is an excellent alternative and it's blazingly fast! Xara's prices have come down out of the stratosphere (I think they're going open source eventually) so you get power and flexibility in a relatively inexpensive package. It may lack a few features that Corel Draw has but it makes up for it in usability and speed.