Believe it or not, from some of the stories I've heard from my boyfriend, it's the "patent pending" status that seems to carry the most weight. He's currently engaged in a licensing dispute with someone who has had patent pending status on an invention for ages. It will likely NEVER get patented, but she and her attorneys play every game in the book to keep it pending...file, extend, appeal, etc. As long as it's pending, the competitors are motivated to license the product from her rather than copy it outright, just on the off chance that the patent should ever be granted...they're making too much money on the product to risk her turning around and suing for damages if they infringe and she actually gets the patent issued, even though they could roll the dice that it's more likely than not she will never get the patent as the claims are currently written.
It's not just patents either, but copyrights are another huge issue, and becoming a bigger issue because changes in the copyright law reverted a lot of materials from public domain back to copyright protection, which really made a huge mess for those already using those materials as public domain.
It's sometimes interesting, because I'm an academic scientist and my boyfriend is an intellectual property attorney, so we don't always view patents and patent regulations the same way. The same convoluted regulations that keep him employed are what make my profession more costly.
Bringing U.S. regulations in line with other countries has both benefits and drawbacks. There are more benefits from the patent "first to file" approach, but the mucked up copyright laws we have now also were partly a consequence of bringing our copyright laws in line with other countries, which completely reclassified materials in terms of their copyright status. First to invent vs first to file will really make a big overhaul in regulations, but then the other issue will be whether that will apply only prospectively or retroactively. If it applies retroactively, it'll make a mess of pending cases, and existing patents, just as it did with copyrights. Changing the law to first to file will certainly wipe out the companies that pretty much just buy up portfolios from inventors with the intent to sue for infringement even though they've had no hand in the inventions themselves.