Maximum Number of Virtual Servers that can be created on BIG-IP LTM 2000S appliance?

There is no defined limit. Object creation is limited only in the amount of space and memory that the configuration requires to store and process objects. A 2000S has the same memory size as the older 6900 and roughly the same capacity. So if I had to take a guess, you'd probably see degradation (ie. slow config updates) between 2000-4000 objects (depending on what's configured).

We've done informal testing of a 2200S and seen 4000 virtual servers (4000 virtual addresses as well), 4000 pools, 12000 pool members (24,000+ objects total). At that level of objects, it can take up to 10 seconds to make a config change in the GUI. You'd probably want to start looking at using tmsh or iControl for management changes when you get into this level of object counts.

Plan on halving these 2200S numbers (or doubling the time it taks to make a config change and save it) for the 2000S.

Aaron