According to numerous sources, Apple last night disclosed the specs of its rumoured Power Mac upgrades, briefly posting details of its much-anticipated Power Mac G5 to its online Apple Store.

Top-of-the range in the new G5 series is a dual-2GHz model, followed by 1.6GHz and 1.8GHz single-processor models.

Additional specs include: up to a 1GHz processor bus; up to 8GB of DDR RAM; AGP 8X Pro graphics cards from NVidia or ATI; three PCI or PCI-X expansion slots; three USB 2.0 ports; one FireWire 800 and two FireWire 400 ports; and optical and analogue audio in and out. The Macs are Bluetooth- and AirPort Extreme-ready, and carry ATA hard drives.

Apple never comments on speculation or on unannounced products.

Apple now seems likely to announce its new Macs Monday June 23 at 10am (6pm GMT) when Apple CEO Steve Jobs delivers the keynote speech to the Worldwide Developers Conference in San Francisco.