[EDIT] The last version of MAMP with the last version of OSX Yosemite works fine.
I installed the beta of Yosemite two month ago, no problem with MAMP. With the last
I still needed to use envars so I was able to work around this by removing the following from the file. Found some errors when launching through terminal related to this
if test "x$DYLD_LIBRARY_PATH" != "x" ; then
DYLD_LIBRARY_PATH="/Applications/MAMP/Library/lib:$DYLD_LIBRARY_PATH"
else
DYLD_LIBRARY_PATH="/Applications/MAMP/Library/lib"
fi
export DYLD_LIBRARY_PATH