I converted Fast and Furious HD DVD to blu-ray a few weeks ago with the guide from doom9.
But Transformers is not doable because problems with converting DD+ to DD, at least for me.
People who pushes these freeware authors are mostly PS3 owners (or blu-ray guys) who wanted to watch HD DVD exclusive titles on their players. But in following months we will see all in Blu-ray so given all the lengthy procedures and steps and decoding time, it is not worth anymore to convert HD DVD to Blu-ray. But I had a fun time and proud feeling after successfully converted the movie and watch it on PS3.