I purchased DxO for the Mac recently, and thought there was advertised an integration with Lightroom. The Mac version isn't yet available in v. 6.
The pdf about the subject, which seems to be focused on v.6 for Windows (doesn't seem to be a previous version available on website), shows several ways of integration- the first is to process in DxO and then import the TIFF (or whatever) into LR2- I see nothing "integrative" about that, as any raw converter can do that.
The second option, make DxO an "Edit With" option you can choose from within LR2, is supposed to be able to send the original raw file (as I understand it) over to DxO without any LR2 adjustments you may have made. This would be a decent option, but it doesn't work, and apparently DxO agrees.
I'd be interested in knowing if any DxO users, especially Mac, have figured out how DxO 5 integrates with LR2. I much prefer using LR2 to make my decisions as to which images I want to keep and which of those I then want to further process, first doing the raw conversion of those in DxO and then having the resulting TIFF sent back to LR2 to be stacked with the raw file and the TIFF further processed in LR2 and/or CS4.