No. While the Track class has a boolean Hidden attribute, setting it to true of false has no affect. It is not a documented attribute so this is no surprise.
If you use a development environment like SharpDevelop (which is free) or Visual C# .NET, you can use the Assembly Scout to point to any .NET DLL (like the Sony.Vegas.dll which is what you are loading when you use the statement “using Sony.Vegas”) it will give you the API for all the classes in it. The problem is, some are supported while others aren’t and there is no explanation of what things are for. So I would use the ScriptAPI document that came with Vegas as the officially supported API.
True, but that obviously changed for V5... in V4, setting the Hidden flag actually did make a track invisible in the GUI (4.0e, build 239). But the track did not mute, and actions like splittings of events, did take place in hidden tracks the same way they'd take place in visible tracks. Also, the hidden flag was not stored in a .veg file (the track became visible again when loading). I always considered this as a potentially useful feature (particularly now as there is track nesting - it could make dealing with many-track-projects much easier if they could be hidden) and asked about it in this forum, see this thread.
Also there was a "Locked" flag, probably to lock a whole track. Which I'd also consider as useful.
Too bad they decided to completely remove this feature for 5.0 :-(
What you could do though is moving selected tracks to the very bottom (rearranging) and hiding/unhiding all events on them. By marking tracks (using its name or its index field) it could even be possible to memorize certain "track layouts", comparable to the window layout (Alt-D-keystrokes), maybe including locking/muting. Maybe such a script exists somewhere, or if there's broader interest, something like this could basically be be done.