Azureus/Vuze was never lightweight, and does not appear to have died. And uTorrent didn't begin to bloat out until after it was acquired by BitTorrent, Inc..

Edit: I think by partners with shady company you mean the malware company, not BitTorrent, Inc.. Just like Vuze has 3rd-party malware. Coincidentally (?), some Vuze malware reports mention Yahoo! being surreptitiously enabled just like the article.