See, I'm not sure this is Apple-envy. Apps aren't particularly new, and although Apple were the first to really push them, they were there before that on the web too. Basically most web-applications (note: "web-applications", not "web-sites") are "apps". They're a bit richer than a page; not quite as rich as a full application. You visit there quickly to upload your receipts; to check on some stats; to read and compose email.
Apple-envy != App-envy in my book. My issue with Microsoft (and interpretation of Apple-envy) is that they want Apple's massive success and they see adopting Apple's arrogant style of "We know better than you" to dictate this curated experience they call "Windows" today as the path to that success. The desktop and desktop technologies also fall victims to that same mentality because those technologies don't provide the shiny they see Apple having success. What's funny is IMO WPF/SL could have provided the shiny but Microsoft's Windows division thought otherwise.
WinRT isn't about "killing the desktop". It's about giving the Windows platform what customers have wanted for ages: glorified websites, and glorified flash games for $2 a time. The Desktop will still reign supreme for your big applications - your teir one games; your high-frequency trading applications; your applications bursting with functionality like Visual Studio and Office - for the foreseeable future.
That's all fine and good but where's the continued investment in the desktop? Why are desktop features being removed and/or migrated to the Windows 8 Store App environment?