In Lightroom’s Import dialog (and in the Library module), you are given the choice to convert your camera manufacturer-proprietary raw files into Adobe’s raw file format, DNG.
I have gone back and forth on recommending conversion to my students, and in my own workflow — not because I don’t trust Adobe’s conversion, but because I just have never seen it as mission-critical. While I could see some advantages, they just haven’t been that compelling to me, and converting to DNG does make the Import process take a lot longer. (At this point I do convert, but I don’t feel strongly about it.)
Though still not mission-critical, Lightroom 4 is introducing some new advantages, to make Lightroom performance faster with DNG’s than with proprietary raw files, and to allow lossy compression.
Here is a great article from C-Net: Adobe Offering New Reasons to Get DNG Religion, on what’s new, and on the advantages and shortcomings of DNG.
Do you convert now? Will you with Lightroom 4? Do comment with any thoughts.