Yup, Nexus 7 has always had a locked boot loader but Google has never made them hard to unlock pretty much on purpose. If the new unit is as good as the last one, look for Ubuntu and the others to have it's skirts up around its head before it actually starts shipping here in the USA. Did you know you can actually replace a battery in a Nexus 7 without having speciality case opening tools?
YES -- OPEN SOURCE IS THE WAY TO GO WITH UTILITY TABLETS IF YOU HAVE ANY GEEK TO YOU AT ALL. Nothing open source really dies, if you can find a forum that supports it that is.
My wife has no geek in her, but she has geek buddies who are all Apple users, as is every female in her family save one or two. They support her tablet uses and she has developed a lot as an Apple tablet user.
My wife also commonly sits down at my white box PC and types emails and stuff, so she is unknowingly becoming a Linux user (not that it is hard by any means, in fact what I use in Mint 9 still looks the closest thing to old Win XP of anything out there).
==============
Firefox is rewriting their core code on all their products into the RUST language instead of the GEKKO they used in the past. Rust supports multiple multiple processors and 64 bit much better than Gekko, which tends to use the first two cores effectively and lets the rest kinda idle along.
Android / Linux has already got their support ready for the 64 bit "sea of cores" thing and is in hard beta testing right now on a completed code base.
These guys had better hurry the heck up .... they only got six months or mebbe a year before they are eat up with Quad Core and Hex Core and Octa Core 64 bit this and that. And folks really ARE going to expect it to be noticeably faster when it runs their old standard stuff -- it should be, you know.
Google Chrome browser has already been rebuilt as part of Google's efforts with big fast Chrome OS laptops. This rebuild has created a fork in Webkit, which will resolve itself through Linaro's interactions within the next few years as 64 bit everything becomes prevalent.
http://liliputing.com/2013/04/google-forks-webkit-introduces-blink-rendering-...===========
Google Play Store is lousy with 32 bit apps right now, but ARM has made their designs so they will run a 32 bit app in 32 bit mode, just dual executing when the software supports such activity on a 64 bit processor.
===========
WILL ALL OF THIS CHANGEOVER STUFF BE SEAMLESS AND EASY ???? Heck no, Some apps will choke at the 64 bit changeover because they were poorly written and haven't been kept up properly. Too bad, then some new 64 bit replacement apps will take them over very quickly and they will drop off from the face of the earth and nobody will miss them.
Open source will continue to tune and improve the 64 bit experience for at least several years until ARM and Linux/Android drop the 32 bit support coverage thing and go with a straight 64 bit coverage. By then all your old mobile equipment will have aged out, or you will have to intentionally seek out 32 bit versions of whatever you use.
I am proof that the open source stuff doesn't just die on you like Microsoft's stuff did -- I am typing on a Mint 9 box that hasn't been actively supported by Mint for a while now, it just keeps on keeping on ....