Not much interest has been taken in either drive....nor has there been much interest in DVDRW drives from either manufacturer for some time now.
Going just from past brand experience, I think folks would recommend the Pioneer over the Samsung, though the Pioneer is a rebadged drive from another manufacturer (though, effectively, it is its own drive, since the OEM manufacturer doesn't typically release its drives on the retail channel). Even with Pioneer's DVDRW drives not being of its own design, the drives have still been quite decent.
Samsung's efforts in-house haven't always been great, but it appears that the SH-224BB might be decent. Decent, not great.
Most people push for the Optiarc AD-7280S drives these days rather than a drive with a MediaTek chipset, or if they do go MediaTek, they go LiteOn (or Plextor or HP).
But between the Pioneer and Samsung, I'd go Pioneer.
[Also, an opinion on release dates: it's hard to pin those down. A drive may be released in Asia before Europe before the Americas...but it's not given that we can track down the first of the release dates. I believe they are both 2012 drives, likely 2nd quarter releases.]