Alright, so hopefully I clearly established why I think this “upgrade” fails... Lets look at what you can do about it.
First off, don't “upgrade” – if you are free version user don't pay the $590... and if you are an existing Pro user don't pay the $95.
This next bit is going to anger a lot of people and I can't help that – furthermore, it's not really their fault and they will be penalized for that, but there is a real need to motivate this particular group to speak out.
What I am talking about is 3rd party developers – the user should not purchase any plugin that is made for 2013, nor should they purchase any plugin that they believe fills a need that SketchUp should fill in-house (as part of SketchUp proper). The reality is that the 3rd party developers have the largest voice in Trimbles ear here. By the user base withholding funds they (3rd party developers) will become much more motivated to speak out and apply real pressure to make Trimble change course. Conversely, if the users keep the stream of revenue coming, they have very little motivation to rock the boat.
Obviously, that creates some additional hardships for the user – but remember the real responsible party for any hardships you endure are Trimble and the SketchUp team. Free plugins are obviously exempt from this... and I do encourage you to donate if you can.
Furthermore, I think it imperative that users take on an additional software package (if they have not already done so) – by supporting a competitor of SketchUp you are applying additional market pressure to Trimble... which in turn should result in better future SketchUp updates for everybody. There are many fine packages out there to choose from, each with their own strengths and weaknesses. A few I think are particularly worthwhile looking into are listed with links below:
bozai3d or form.z
Rhino3D
MoI3D
Blender
If you cannot afford to financially support a commercial SketchUp competitor, then support the Open Source movement by using Blender. Supporting Open Source software applies pressure to the entire industry to step-up their game and can only improve the competitive situation.
Do these things and you will be applying pressure in ways that Trimble cannot ignore.
Adding a response to this thread also applies pressure, and I encourage everybody who is dissatisfied with the status quo to post, even if it is only to say "I agree". The mortal enemy of change is apathy... conversely you can change things by simply banding together and speaking out (with keyboard and wallet). They do read this stuff -- it's a fact.
Best,
Jason.