Two sound modules to throw into the pot.....

Muse Research - Receptor
SM Pro Audio - V Machine

Both however are not true open tech and require Wizard files to get the VSTi's running. The V-Machine is also limited in power and probably not suited to running Modelling technology but I said I'd just mention it anyway because these kind of devices are rare.

One to watch will be Lionstracs and their Rack Unit which is on the way. In my opinion this is going to blow the entire market wide open and will be hugely popular.

Regards
James