Since the inception of Xbox LIVE (to soon be called Xbox Live, without capitals), the way of purchasing arcade games on XBL, movie content, in-game purchases and DRM was to invest in Microsoft Points (MSPs). Typically some small DRM would cost 80-240, an arcade game would be 400-1600, and move purchases varied. Users could either hook up their bank card to the system and purchase points, or order points cards from retailers. The limitations of the system meant that users were always looking at retailers for the best deals on points, even if it only scraped 5% off the cost. Now Microsoft are changing all that.
As of the next update to the Xbox 360, all purchases made on Xbox Live will be done in local currency. Users will have to register their account with a bank card (or in the US it is possible to use the pre-pay VISA cards) in order to make purchases. This makes things simpler in terms of not having to deal with an extra currency, and allows Microsoft to charge region specific prices for arcade titles or additional content (as per their licencing fees with media production studios). The obvious downside will be the outcry when a title is substantially cheaper on Xbox Live Canada or Xbox Live India (for example) over their native Xbox Live pricing.
As you can imagine, users have no say in the matter, and the questions arise as to what will happen with users who currently have points in the bank. These will be converted into local currency credit where the account is based, at an equivalent or greater value. MSP cards that you can buy online (e.g. 2100 MSPs at Amazon for £16.87) will be honoured for the time being, accepted ‘until further notice’.