This, people, is A Big Deal. Pioneer has been the champion of the DVD-R/RW format since before DVD+RW drives were even available. Pioneer has manufactured the DVD-R/RW drives that went into Apple computers as the SuperDrive and into Sony VAIO desktops, as well, not to mention Pioneer's own DVR-A0x series of add-on drives available through retail, of which the DVR-A06 is the latest generation.
Meanwhile, the DVD+RW format has been taken up by Dell, HP, and Verbatim, among others. Then, as if things weren't clear as mud already, Sony introduced its DRU-500A combo drive which will record to both DVD-R/RW and DVD+R/RW media. Now it seems Pioneer is following the same path.
So where does this leave the recordable DVD format war? Good question. As I noted earlier this month, it's more of a spat than anything, since at worst consumers will have a drive that will read and write one recordable format but will only read the other. With Sony and Pioneer producing combo drives like the DRU-500A and the DVR-A06, even that relatively minor issue becomes less likely.
Still, if I had to venture a guess, I'd say this move means good things for the DVD+R/RW format in the long term. Why? Because Pioneer was one of the major manufacturers of drives that only supported DVD-R/RW. If integrators who were using Pioneer drives in their products (such as Apple) switch to the DVR-A06, you're looking at more dual-format drives at the expense of DVD-R/RW-only drives. Meanwhile, manufacturers such as HP and Dell will likely continue to ship drives that only support DVD+R/RW. Over the long term, that means a larger percentage of drives supporting DVD+R/RW and a smaller percentage supporting DVD-R/RW.
Of course, that's just idle speculation; I stopped trying to actually predict this stuff a while ago. Basically, every time I think the recordable DVD situation can't get any stranger, the market proves me wrong, and this development is no exception.