At least in the South Korean domestic market, Samsung is selling their first "DVD Multi" drives OEM'ed from Panasonic of Matsushita, Japan, and BeAll DVD-R media developed and manufactured deep in the tech center of Samsung's key engineers, in Suwon city, south of Seoul. 50-disc BeAll DVD-R pack is included in the DVD Multi T03 package. I am very little interested in the product offering but I can guess it is an Panasonic LF-D521JD.
Why Samsung has no DVD+R or DVD+R/-R drives yet, I can explain in details but it could get boring easily. LG is a bit ahead of Samsung right now. Of course, Lite-On is much behind of the two South Korean electronics conglomerates. Though Lite-On IT is a company I now work for through other international trading companies and distributors and LG and Samsung are the most serious and direct competitors to me (if you are curious about this, check liteonit.co.kr and it is not an ad since the site never sells anything to anyone outside South Korea itself), I have no doubt in thinking Lite-On is not a serious threat to them. South Korea is run differently from Taiwan and Japan.
I have talked to some BeAll-related people. They are mysterious. I have talked to some Infodisc-related people. They have left me similar impressions.