Sharing Vim Yank Register
Solution 1:
Have a look here: Using vim/gvim with multiple... Looks like it is on a todo list for the dev's
Solution 2:
In case the main thing you don't like about the "+y solution is the extra "+ typing, here's how to make the default y/d/p/c register (the so-called "unnamed" register "") system-global:
:set clipboard+=unnamed
When the "unnamed" string is included in the 'clipboard' option, the unnamed register is the same as the "* register. Thus you can yank to and paste the selection without prepending "* to commands.
source: last paragraph of :help clipboard