I have what may be a dumb question, or maybe it's here in the 30 pages, but would windows/linux/etc. still run in a virtual environment with ARM processors?
Short answer (as already given): it won't run
x86 Windows or
x86 Linux with anything like the efficiency of a x86 Mac. Potentially, they could run under an emulator/translator that simulates an x86 chip in software but that is likely to be horribly slow.
If you currently rely on this then you probably won't want to be queuing up for an ARM Macbook on day 1 (although you might want to "think different" over the next few years and look at alternatives).
More complex answer: in theory, it could run ARM Windows and ARM Linux efficiency - there are several ifs, buts and maybes to do with system architecture/firmware that would affect whether an ARM equivalent of BootCamp was feasible, and we can't know the answer to until Apple finally announces something. Also, it's up to MS whether they license ARM Windows for Mac hardware. Whether Parallels or VMWare Fusion would get ported (they're
not going to be a case of 'tick the ARM box and re-compile!) with no market for x86 Windows is a good question - but MacOS has basic virtualisation support built in (as used by Docker for Mac) and ARM chips
do support virtualisation - but AFAIK that doesn't include graphics access, so it would be mainly good for server/command line stuff.
At this stage, ARM Linux is pretty well developed with tons of compatible software and (say) Docker running on ARM Linux would be a very useful tool for web/server development (most of which doesn't give a wet slap what processor it is running on and
at worst you'll only need an x86 for later-stage testing of any binaries you produce). ARM Windows, however, is probably
not what you wanted Windows for, although it does have x86 translation/emulation for Win32 apps (64 bit promised) and while the reports on the performance of that are... underwhelming it should be
much better than running x86 Windows under emulation (...because only the application code is being emulated whil all the operating system calls, UI rendering etc. are running natively).
However, Tim Cook isn't going to break into your house the day after WWDC and take away your Intel Macs. Apple have
just launched the Mac Pro - which will probably be the last Mac to go ARM, if only because of all the obscure third-party plug ins that pro media types rely on - and if they don't support/update that for at least 3-4 years it will be nature's way of telling you never to rely on a single hardware vendor for anything important.
Looking long-term: MS seems serious about ARM Windows this time around - it is early days at the moment but it isn't dead yet, and a lot of
modern Windows-specific software development is using the .NET framework which is processor-independent (not to mention the increasing importance of web-based and mobile development vs. traditional Windows apps). For non-developers, things like banking and tax apps that, previously, have tied people to windows are increasingly being replaced with web apps. Give it another few years, and Windows x86 binaries could be the sole domain of hardcore gamers and corporate computing - neither of which have ever been Apple strong points.
As for Linux - that's already mostly about servers/web development (most major Linux apps have MacOS versions anyway - it's not like you need a Linux VM to run LibreOffice or Inkscape) which can either be done in ARM Linux, a x86 Linux instance in the cloud or a cheap PC sitting in your basement. Yes, you'll need an x86 box to compile/test on if you're working on traditional Linux software - but, increasingly (with Amazon and others rolling out ARM-based servers and a zillion users with Raspberry Pis and Chromebooks), you'll need to compile/test on ARM Linux
as well.
One of the strengths of Mac and MacOS is that it
isn't pinned to the past by legacy code the way Windows is - it would be a shame to let Windows hold it back. Even if Windows compatibility was a selling point back in 2006, there have been huge changes in the computing world since then.