When I think of this concept of a "Westphalian World", I think the following principles are necessary:

1. States are the primary actors in the international system
2. States are sovereign and have a monopoly on power within their territories

So my answer to your question is a qualified yes. States are still the primary actors in the international system; governments control the legal, political, and economic mechanisms that regulate populations and their activities, from trade and migration to war and humanitarian aid. Your legal rights and identity are dependent upon your citizenship in one state or another. States are still treated equally before the law, though this may not always be the case in practice for a number of factors.

So, my qualifications: there a couple of countervailing forces with trends contridicting the core of a "Westphalian World". First, globalization (essentially capitalism applied globally) is not dependent on a system of states. Capitalism has been at the forefront of destroying the boundaries between states while simultaenously reinforcing the legitimacy of states to regulate commerce (in favor of capital naturally). The result is the collection of capital norms as strong or stronger than Westphalian practices (i.e. global free trade vs political sovereignty to determine trade policies).

Second, states are now much more complex than their counterparts from previous generations with multiple layers of identities, rights, bureaucracies, stakeholders, and powerbrokers. In weak or failing states any of these components may be stronger than the actual state in practice - but does that mean we have transitioned from a "Westphalian system" to something altogether different or does it mean that the state in question is a failure?