Over the years RIM has always released multiple builds of the internal dev devices before launch so this is really no surprise. Recently some sharp eyed souls noticed that RIM had even posted a render of a revision called the BlackBerry 10 Dev Alpha B on RIMs developer website. RIM quickly pulled it down and the speculation continued.
@NerdBoss514 couldn’t leave it at that and asked @BlackBerryDev on Twitter and actually got a response. Here is what they said:
They then followed up detailing some of the small changes coming for some future devices. RIM has confirmed that they will be giving away more of the devices before the launch of BlackBerry 10 so that may be when we see them probably around BlackBerry 10 Jam Americas. There are also rumors that they changed some of the components due to them being changed by manufacturers.
Kudos to Bla1ze @CrackBerry for pointing out the conversation