The alleged dates come from French site MacG.co, which believes new 13- and 15-inch MacBook Pros will be available for sale either Oct. 24 or 25. It's expected that Apple's new professional-grade notebooks will feature Intel's latest-generation Haswell processors, which offer significant savings in power consumption, thus improving battery life.
As for the new Mac Pro, which Apple already gave a sneak peek at earlier this year, the site claims that the new desktop will be available for delivery on Nov. 15.
The site also claims that Apple's fifth-generation iPad and second-generation iPad mini will go on sale either Oct. 30 or 31. It's unclear whether that would be the date orders would begin, or if the devices would be available to physically have in hand.
The iPad dates are somewhat suspect, as Apple traditionally launches new iOS products on Fridays. For example, last year the Wi-Fi-only versions of the first-generation iPad mini and fourth-generation iPad went on sale Nov. 2, on their way to total sales of 3 million total units in the first three days of availability.
Apple is expected to announce dates for multiple new products at a media event anticipated for Oct. 22. With that date just a week away, it's likely that invitations to members of the press will be sent out later today.