Since we will migrate to a new system, I'll announce a few changes to the API so people can be ready. It shouldn't cause any compatibility problem for most people.
It will be possible to issue API keys for your account, with limited or full access, and revoke those keys. You can however still use the API for full access with login and password
Trade IDs will be much larger, and no longer in sequence. Old trades will keep their old IDs. New trades will have an ID which correspond to the trade execution time in microseconds, for example: 1308609708628581
Order IDs will become UUIDs. Old orders will have an UUID assigned to them. An UUID is a 36 characters long string made of hexadecimal characters separated by a dash. Example: 1f0b3734-ddf3-47e8-badb-a85a700c61d9
It should also be noted that the way the whole system works will be a bit different. When an order is placed, it may have a delay before being executed, if the engine is busy. The trade will be put into queue. Additional API parameters will exist to allow trades to be non queued (return failure if engine is busy), have an expiration in queue, do not cause creation of an actual order after being executed if full execution was not possible, or have an expiration as an open order.
Other changes will also be made in the future, however they should be compatible with existing implementations.
https://support.mtgox.com/entries/20208658-changes-to-the-api
Long Live MtGox!
