I see that Warlord are about to release a 3-in-1 kit of the T-34/76. It will have three different 76mm turrets, including 2 1943 variants. I think I mentioned before that I wished Rubicon had supplied a 1943 turret with their T-34/76 - it's a lovely kit, but I think many wargamers would have preferred to be able to build the later version. Anyway, the T-34/76 comes hot on the heels of their Tiger I, which also duplicates Rubicon's excellent 3-in-1 Tiger I. And I see Rubicon are considering releasing an M3A1 half-track, even though there's already a Warlord kit available (albeit a pretty mediocre one).
While a bit of competition between what are the only 1/56 plastic kit producers is a good thing, and pushes both to improve their game, I'd hate to see a situation where both companies keep trying to one-up each other with kits of the same vehicle. I guess both companies want to have kits of the best-selling vehicles. But since they're primarily aimed at the wargaming market, there's a limit to what most customers will want from a kit. In other words, unlike the situation with the 1/35 scale military market (where companies like Dragon keep releasing increasingly more refined versions of the same vehicles), there's no real demand for the 'ultimate' Tiger kit. There is a huge range of vehicles that people are waiting for, many of them less glamourous subjects than the Tiger and the Panther. I suspect Warlord can be counted on the focus principally on 1944-45. Hopefully Rubicon is thinking more laterally - the pre-1944 period seems like fertile ground. And vehicles like trucks and armoured cars would be very welcome - they are in many ways more useful for games like Bolt Action, where (apart from Tank War) vehicles play a supporting role.