I have resumed a couple of downloads. As far as I can tell, it works quite nicely, although sometimes LimeWire seems to bitch around a little, when downloading a file of exactly the same file size and the same file-name. It sometimes starts a new download anyway (usually if I download it from a new host). This will probably improve when hashing is added.

Maybe you want to try the new alpha version from limewire.org, it seems to work more or less and already supports swarmed downloads, although you have got to take care, you download files of exactly the same file-size and not just files, LimeWire believes are about the same. Especially mp3s are often broken by swarmed downloads without hashing...