I would say worldwide launches are best. However, they should be met with the planning showed more by Nintendo than sony/MS.
MS rushed the product with no where near the expected demand available.
Sony did not have a worldwide launch. They realized that they would make the same mistake MS did and decided to hold back on EU/AUS. Thier stock levels reached ok levels in January or within 2 mos of launch. Which isn't really that bad or out of the ordinary.
Nintendo really tried to do it right. They aimed, and nearly got, 4m out in a little over a month. Under any other system launch that probably would have been really good for normalized stock to be seen in January. However, they completely didn't see the huge demand and thus are now scrambling to quickly increase production before PS3 gets any big guns on the table and tries to make a comeback.
Basically, if it is done right with a huge amount of stock released on launch, it should be fine. However, judging that initial amount of stock is the tricky part. PArt of the buzz that has helped the Wii has been its worldwide launch. The reports of being sold out world wide and lines in every region, created a lot of positive free news.
