There is no way you're ever, ever going to stop abuse of the patent system. That is, unless you completely and totally abolish all patents in all areas. No more patents, no more USPTO, no more abuse. As any libertarian will be happy to point out, if you put a gun in someone's hands and give them the legal right to use that gun for whatever their purposes is, you're going to have a huge mess and abuse of power. That's government for you. Patents are unnecessary, morally unjustified, arbitrary and extremely prone to abuse. There is no possibility of ever making an objective statement about what can and what can not be patented, or how long a patent should last. It's impossible. If you say 20 years - I say why not 21 years, why not 20 years and three days? Because you say so? Because the State says so?
Further, patents are legal monopolies and basically an infringement upon property rights. If it is my steel, my wood, I'm going to build exactly whatever I want to build with it. I don't care if you've invented it before, it's mine, mine, mine and you have no right to stop me. Neither does the State. Software patents are even worse. I'm going to put ones and zeros on my disks, and what those ones and zeros do when put through other ones and zeros is none of your business. Get off my property! If you invent some new metal alloy twice as strong as steel, well, congratulations. You own some metal. You do not own my metal, I repeat: you do not own my metal. If I make the same alloy as you do, well, bad news for you. It's called competition. Welcome to capitalism, dude.
Now you say, won't people stop inventing stuff? Yeah right. Ever heard of that invention, the steam engine? Watt's patent stopped others from building better engines, and most of his time and money was used not to build steam engines, but to lobby the government and collecting royalties (See Against Intellectual Monopoly, chapter 1 for a longer discussion of Watt's patent and how it stopped progress.). Further, they stop many new inventions. Just look at Blackberry. So much for patents and innovation. As the old joke goes, if pro is the opposite of con, congress is the opposite of progress. No other organisation has hindered progress more than the coercive beast that is government.
Moving on, the argument that no one will develop expensive stuff is completely false. First, it's just another protectionist argument, one that relies only on what is seen and what is not seen. With patents, you see X dollars being invested in developing Y. Without patents, what would those X dollars be used to do? You have no idea, I don't, no one does. We can't prove that society benefits from X being developed instead of some Z, W or Q. Secondly, the argument shows a huge lack of economic insight. No person can predict the future, or the future economic situation. If so were the case, no humans would act (Rothbard explains this in Man, Economy and State). Ok, so say company X develops some miracle drug. You think company X would need a patent, to prevent free riders, people who rip off the product and sell it cheaper because they have no R&D costs. Ok, well, how are companies Y, Z, Q going to know that the drug is a sucess? Isn't success defined as earning a huge profit? Well, then, when the drug is a success, company X has obviously made a lot of money from it. Arguing for patents because of free riding effects is stupid.
Imagine you're in a race. You try to imitate the guy who wins, to win yourself. However, to know what he does and who he is - you have to let the race progress and let him win. That'll help you, I'm sure. You cannot know who the winner is before he has won, and then it is too late. That's what the free rider argument is all about.
As we have seen patents are no more than arbitrary government monopolies given at the whim of some random bureaucrat, in effect giving someone the right to control what you do with your property. Further, they are an obstactle for innovation, and protectionist. They are clearly nothing else than a pure, counter-productive government intervention into the economy and an abuse of governmental power.
Support property rights, help innovation, abolish patents.