As you may know, Maine went from one device to three in the latest round of MLTI 1:1. Less than 10% switched from Apple to HP. The rest used either iPads or MacBook Airs. The program migrated into many high schools a few years ago, so not just 7+8 are involved any more.
One concern at the initial announcement of that change last spring (had been the same platform/device for the past 10 years) was the fragmentation of Professional Development. The older model would not longer work for 100% of those MLTI users. Change isn't necessarily a bad thing, but in this case PD had to refocus somewhat to include different OS (OSX, iOS,Windows) and different work flows. No longer would one size fit all.
As I said, that change isn't necessarily a bad thing. The challenge now is how do those MLTI users share and remix across those different devices from one part of the state (or one town) to the next?
If I had to make a choice about a 1:1 program, I would want one "standard" device/OS, a "standard" software load," and a way to gather as many as practical into PD sessions that would assist them in how to make the best use of the device. (Of course, BYOD brings in similar concerns.)
When the device field is scattered, all of the rest becomes more challenging.
Students seem to have no problem with navigating between devices, so it's my guess that this is a concern of (us ?) digital immigrants and IT Directors. Your question is also about  how students show what they know in the variety of ways they have available to them via technology.

Brad Edwards, Technology Integrationist
Learning With Technology Daily: http://paper.li/BradEdwardsVT
"The secret of education lies in respecting the pupil." -Emerson
On Sep 25, 2013, at 9:23 AM, SCHOOL-IT automatic digest system <[log in to unmask]> wrote:

From: Raymond Ballou <[log in to unmask]>
Subject: planning for 1-1 for next year
Date: September 25, 2013 8:29:13 AM EDT

Dear All

Our existing 1-1 program had/has constraints that made planning easy.

The number of teachers was limited and the choice of device was limited.

Anyone have any suggestions about how to make the transition from 3 teachers and no choice in device to 15 teachers and any number of choices in device?

Our class of 2018 will be moving out of our middle school 1-1 (existing program) and into our new high school 1-1 program (does not exist yet).

Obviously choice of device will/should be the LAST thing on the planning agenda.

Anyone have a timeline or scope and sequence for this kind of thing?