The former Soviet Union began developing a successor to the Sukhoi Su-24 strike aircraft (which was its attempt to counter the US F-111) in the 1980's. Thanks to the collapse of the Soviet Union and budgetary and other constraints in Russia, which took over the development, the new Su-34 limped along slowly in development. The first production aircraft only entered service in the 2005-2007 time frame. A handful of the aircraft saw combat over Syria last year and earlier this year.
The Su-34 is based on the very successful Su-27/30/35 family of fighter aircraft, but with a two-seat side-by-side cockpit and significant structural modifications to suit it for the bomber/strike role. It can carry up to 13 tons of external stores and ordnance over a combat radius of 600-700 miles, and reach a maximum speed of about Mach 1.8 or thereabouts (Russia hasn't been very forthcoming about its performance).
Here's an interesting video from Russia of two Su-34's tasked with bombing ice buildup along the Sukhona River last week, to break it up and enable the spring thaw to proceed more quickly. They aren't carrying much ordnance, which allows us to get a good look at their lines. They certainly show a sprightly take-off performance. Watch in full-screen mode for best results.
Their Achilles heel is likely to be their engines, as always with Russian military planes - they're unlikely to achieve more than a few hundred hours without needing a major (i.e. factory) overhaul. The Su-35, latest generation of the fighter family from which the Su-34 is derived, has a service lifetime of only some 4,000-5,000 flying hours, so I'd assume the Su-34 has a similar limitation. That's not a lot in comparison to some Western airframes. Still, it's likely to be a very good performer despite those limitations.
(I can't help smiling at the sight of the Su-34's nose and cockpit. For some reason it reminds me irresistibly of a duck-billed platypus!)