They may be monocoque looking, but the actual contruction still uses distinct lugs and tubing with an overlapping miter. The following bikes are made with lugs and tubing:

Colnago C50
Carbonframes Sapphire (-> Lemond after buyout)
Calfee Luna, Dragonfly, Tetra
Crumpton
Look
Parlee
Serotta MeiVici
CR1
Trek OCLV
Specialized

Monocoques: no lugs with continuous fibres through the joints

Aegis
Look KG196, KG496
Colnago C35, Carbonissimo
Isaac Sonic
Merckx/deRosa axm


There are numerous variables in manufacturing. Cost is always a variable that needs to be considered and there are pros and cons to both true monocoque vs. tube/lug construction. Most manufacturers will offer frames using both methods of construction to hit various price-point targets. There are also corporate bean-counters in the process somewhere making decisions that may not reflect the true custom frame-builder's "art" of frame-sizing and geometry.