This is pretty much what Apple does, release a new product every year or so. Sometimes minor, sometimes major. However, since this is a major platform change, Archos should consider unlocking the Archos 5 & 7 firmware if they're no longer going to support it after the Android (if they're still going to issue bi-monthly updates, then that's fine and no reason to unlock firmware). This would be a good move for a business that has many unhappy customers. A little goes a long way and most companies don't understand such things.
Updates for iPhone or iPod Touch are available for previous hardware generations. The first iPhone hardware (GSM and no GPS) has exactly the same firmware as the new iPhone3G. According to Apple this will continue to be so for several generations. iPod Touch users have to pay 9,99Ôé¼ for every MAJOR upgrade (1.x --> 2.x --> 3.x etc) tough, but they can upgrade also.
I believe Archos should learn from Apple in this regard... however in order for Archos to do this they would need to KNOW HOW TO do this.
From Apple Insider on 17th March:
"... iPhone customers will be able to download the new iPhone OS 3.0 software for free this summer and iPod touch customers will be able to purchase the software update for $9.95. Apple notes that MMS messaging will be available only on iPhone 3G and that fees may apply. Some iPhone 3.0 features may also not be supported by older hardware, such as the original iPhone, citing differences in the internal radio."
Archos has something to learn from this, however are they able to?