The hoary old rumour that Microsoft IS developing a Blu-ray add-on drive for the Xbox 360 gains yet further ground this week, with talk of a possible pre-Xmas launch for the device.

If true, this will mean that Sony loses its key USP with PlayStation 3. Note that the two key words in that last sentence are 'if true'…

The rumour of a Blu-ray drive for the Xbox has pretty much popped up every other week since the demise of the HD-DVD format earlier this year.

Xbit and Toshiba

This time around, Xbit Laboratories is claiming that Toshiba-Samsung Storage Technology Corp has a contract to build external Blu-ray drives for the Xbox 360, which are said to cost in the region of $100-$150 (£50 - £75).

If true, and right now remember this is to be filed under 'rumour', it will mean that gamers can get the Xbox 360 with a Blu-ray movie player for notably less than the PlayStation 3.

Quality, ease-of-use

Whether or not the quality and the firmware updating of the Xbox Blu-ray drive will be anywhere near that of the PlayStation 3's lauded in-built Blu-ray drive is another matter entirely.

TechRadar spoke to a Blu-ray Disc Association spokesperson today who told us, in no uncertain terms, "We do not know anything about this and cannot comment on rumour or speculation."

An official announcement is surely due soon. What we really want to know is whether the Xbox Blu-ray drive gets a pre-Christmas launch or whether it is pushed back to CES in early 2009.