Some additional info.
From early 1990s Tupolev OKB studied theme of long-range airliners of large capacity. On of the projects was the giant Tu-404, the other was not so ambitious (but also big enough) Tu-304. It would carry to 500 passengers on distances to 10 000 km. The aircraft was designed as low-wing monoplane of classic layout, with swept wing (33.3 degrees) and empennage; two tailfins are its most unusual feature. The aircraft would be powered by two turbofan engines with about 40 000 kG thrust for each and specific fuel consumption about 0.57 kg/(kG x hour), mounted underwing on the pyons. They could be alternatively Kuznetsov NK-44 or RR Trent 884.
The design works continued during some years, even the fuselage section mockup was built; different original versions of cabin configurations were studied, considering factors of the aircraft's future multifunctional usage in service. Under condition of normal progress of design works and (the most importantly) stabile financing, Tu-304 could fly during 1st decade of 21st century (and, I think, it would find its place between B-787 and A380). But in 1990s Russia... In a word - the works were frozen. And they are frozen till now...
Wing span - 57 m
Length - 62 m
Height - 19 m
Wing area - 340 m2
Wing aspect ratio - 9.6
Maximum takeoff weight - 245 tons
Maximum payload - 55 tons
Maximum fuel weight - 88 tons
Cruising speed - Mach 0.85
Cruising altitude - 11 000 m
Flight range (with 400 passengers) - 10 200 km
Takeoff run - 3200 m
Source: Aviatsiya i Kosmonavtika magazine, No.10/2000. (In the cycle "Under "ANT" and "Tu" marks" by V. Rigmant).
According to http://aviaros.narod.ru/tu-204.htm, nowadays the designation "Tu-304" is used for projected Tu-204 derivative with two rear fuselage-mounted propfan engines.
Thank you redstar72. I would be interested in any additional Soviet and Russian aviation projects that we do not currently have documented on Secret Projects. Forgive some of my errors, I have been relying on Google Translate.
Same as many other designers/companies. To enlarge the fuselage to the sides is the logical idea until you consider the pressurization problems and passangers not willing to seat in the middle of thousand people on all sides.