It's great to see DVDs increasingly being released simultaneously around the globe, rather than suffering the six-month wait we used to have to endure in R4.
Troy is being released on DVD in Regions 1, 2, and 4 in October 2004. From the information available to me, all these versions will be identical. However, the R2 and R4 enjoy a PAL transfer (as opposed to the R1's inferior NTSC), and the R4 RRP is cheaper than the R2's when you do the conversion. There might also be a few censorship cuts to the R2 version, but I haven't confirmed this yet.
So while there's no overwhelming reason to favour any of these versions, I would prefer ours.