Rubicon's single piece tracks would would very well with the Panzer I and II - there's almost no loss of detail on vehicles like these with narrow tracks and single roadwheels. But they've explained that there are issues with small vehicles like these. One answer would be to keep them quite simple - it would theoretically be possible to fit a Panzer I or II on 1 sprue. And maybe provide 2 (or 1 of each) in one box.
Rubicon have also said they are re-doing the Panzer III and IV, including early versions. That will provide the most important DAK tanks. So we'd really be hoping for some Italian armour (such as an M13/40 + Semovente kit) and at least 1 more British tank, such as a Matilda or Valentine. Warlord have just released the M3 Stuart, so there's no need for Rubicon to do one. Rubicon would in any case probably be better placed to keep focusing on soft-skins (such as unarmoured German half-tracks) and light AFVs (such as armoured cars). These were important in the North African campaign, and I think they are proving to be winners with both BA gamers and modellers.