Very possibly however the rules on buying farmland/forestry haven't changed since before then.
I don't think you can purchase farmland, not yet anyway. I think the law changes in a couple of years, but no doubt someone else will clarify.
Someone else here might be more up-to-date than me, not on the law, but on how it's applied - this is important here. As I remember from old discussions here, you can buy farmland, but the vendor can get in trouble selling it if the paperwork is incorrect - there's a thread somewhere in the archives here that discusses an incident where that happened.
There are also different categories of farmland, according to the quality. It's easier to get permission to buy lower quality farmland (the minister has to approve it) however a lot depends on who the minister is at the time.
Remember that after 1990 and even more in 2004 (EU entry) there was a genuine fear that families would be priced off buying land by foreign (meaning German) buyers. This never happened and in fact there's some evidence that Poles are buying across the German border rather than the other way round. Also there's a heavy dose of political nationalism from some quarters - some people even think that if a foreigner buys land in Poland then that land becomes somehow less Polish and two (largely rural) political parties who have no representatives now had a bit more influence around the time the legislation went through, hence the current law
I think the law changes in a couple of years
Yes - this is true. The provision restricting land purchases has a fixed end date and can't be extended by the government.
Certain nearby countries who joined the EU at the same time have scrapped the provision restricting farmland sales before a certain date however Poland hasn't. You can however buy building land without restriction.
My wife is 3rd generation Polish-American
If she could get citizenship, you wouldn't have any problem.
Can we purchase some country land to live on and grow a few things?
Farms tend to be very small in Poland and some pieces of land that aren't classified as farmland are almost as big, so you might in fact be able to do this.
A warning though. Life in Poland can be harder than many people expect.