Is there any word on the street (or from Apple) that there will be a software/hardware update to allow the Magic Mouse 2 to work with 10.10 (Yosemite)?
Not to be snarky, but there is already a release that does that. It is available from the App Store under the name
El Capitan. Best of all is a
free upgrade.
Apple is highly unlikely to make any new updates of Yosemite unless they are security related. El Capitan is already a mid-life product (OS X 10.11.2 is already at beta 4) and it is safe to say development of OS X 10.12 has already begun.