For a new generation engine, the angle of its V-formation is wider in order to lower the centre of gravity. For example, Ferrari changed the angle from 80 degrees in 1999 to 90 degrees this year. They may have achieved to control the vibration range remarkably. Honda's RA000E appears to have resolved most of vibration problems. To increase revolutions, reduction of stroke length has been boosted.
Shorter stroke makes the radius of rotation smaller and counter balance becomes smaller.
In order to set the dynamic balance at closer spot to pinpoint and do with lighter weight, heavier tungsten tablets are used. Some teams are said to use discarded uranium. Such discarded uranium is not available in markets, but I heard that you can obtain this in Russia. All engine manufacturers will bring a new version of their engines, but FIA is to introduce some stricter regulations on engine control in order to go the limit for car inspections. FIA tries to let some teams, who have been said to use traction control under cover, know its stance to force an end to such illegal behavior.