Last Updated: June 1st, 2011
Update: If you've somehow inexplicably ended up at this article, please note, HTC has since announced the 3D will be unlocked (at some point) and their future policy is to have unlocked bootloaders on all devices.
It seems HTC has finally caved to what are likely the security demands of wireless carriers with its newest phones, and is locking down its handsets Moto-style. Latest case in point: the EVO 3D - which sports the same sort of security we found on the Sensation earlier this month.
Last Updated: April 27th, 2011
Motorola has had a dark past when it comes to bootloaders. Apart from a couple exceptions (most notably, the XOOM), all of the major Motorola devices have had locked bootloaders, and thus, Android customization enthusiasts have been shut out from such tweaks as custom kernels.
Recently, there has been quite an outcry directed at Motorola and their bootloader policy, in the form of petitions and hijacked polls, and it looks like they have heard users' requests.