What happened to my-*.cnf in MySQL 5.6.8?

Question

Up to MySQL 5.6.7, the official RPM was shipping with these files:

/usr/share/mysql/my-innodb-heavy-4G.cnf
/usr/share/mysql/my-medium.cnf
/usr/share/mysql/my-huge.cnf
/usr/share/mysql/my-large.cnf
/usr/share/mysql/my-small.cnf

In 5.6.8, these files are gone, and the only one left is:

/usr/share/mysql/my-default.cnf

I'm not a MySQL tuning expert, and was used to always start with my-innodb-heavy-4G.cnf. Now I am left with a single configuration option:

# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
# innodb_buffer_pool_size = 128M

Is tuning this only variable the magic key to most optimizations, or are there other relevant parameters that I should tune when installing a new server?

In which case, where can I find an equivalent file, that would contain sensible defaults for a InnoDB-only, 4GB RAM dedicated MySQL server?