I hope that Maemo Leste doesn't go to forever update hell (if you upgrade new version of OS you have to install new version of all software or if you want install new version of software you have to install new version of OS).
Where is downcompability like with Symbian/DOS/TOS/System(Mac OS)/AmigaOS/Windows(up to 98SE)
I hope we take versioning seriously and make programming documentation easy to follow what calls works in what version.