Signed or unsigned, you know that these measures won't last long and someone will mod it successfully anyway. Hell, XBOX 360 did the same thing and it was already compromised pretty much as soon as it hit store shelves. I am still pretty ticked off that Motorola went that route, though. My Motorola Droid is the first Motorola cell phone I've ever bought--and it might just be the last one, too. That's a shame, as I'm really--really loving it. Although, to be honest, I've never rooted my phone and I don't see a need to, it bothers me a LOT that they would go out of their way to tell me as their customer that I am not allowed to customize or otherwise do with my own device whatever I want. If I'd bought a car or a house and was told that I can't replace parts, I'd be pretty angry too. A better analogy is buying Internet service and being told that I can ONLY use a computer they sold me and then I can't install any other operating system on that computer. I don't see how my cellphone is any different. I'm paying the telco and the hardware manufacturer for their telco/data service and for their hardware respectively. They should let go of their obsession with controlling their customers.
No I still don't understand Android case. I do understand Apple case - they are both hardware and software vendor, so locking their users to their OS is beneficial. This also monopolizes application store and gives them a % of every sale. But Motorola is not software vendor. But maybe this is a good hint. Maybe locking Motorola users in SHOP4APPS is the rationale behind these moves.
They're maemo and MeeGo... "Meamo!" sounds like what Zorro would say to catherine zeta jones... after she slaps him for looking at her dirtily...