Still Safe
I did my first hunt in Zimbabwe in 2008, in the Matetsi area. You arrived at Victoria Falls and were met by your PH, and whisked away to the concession, a couple of hours by truck. At the end of the hunt I spent two days in Vic Falls, sightseeing and fishing. At no time did I feel in any danger. The people were friendly and welcoming.
This was just after the aborted presidential election, and inflation was more than one million per cent per month (I'm not kidding). There was no Zimbabwean cash to be found, because it was all worthless, and there was nothing to buy in the stores.
I went back in 2009, and hunted Matetsi again for part of the hunt, then drove 6 hours by road to Shangani (near Bulawayo) for the balance of the hunt. You went through about 6 police/army roadblocks in that distance, but they were always polite and we were on our way within minutes, even though we were carrying firearms. (We were polite as well). I spent a day in Bulawayo, and left from the airport there.
In 2009 the economy seemed to be even worse than in 2008 - power outages everywhere, and Zimbabwe had abolished its currency. Only Rand, Pula and Dollars circulated. The stores seemed to be better stocked, but people didn't seem to have any money to buy anything.
Even with that, again I never felt in any danger.
I would point out that in both cases I was with my PH at all times. I'm not sure I'd recommend that you travel alone other than in urban areas. Not enough people speak English and it might be easy to get into trouble, but I'd say that's likely the case in most African countries (and lots of other countries as well). I will say this: I think you're a lot safer from crime in Zimbabwe than you are in many parts of South Africa.
So many people are staying away from Zimbabwe because of the troubles and media reports that the local people are very happy to see you. Last year in mid-July I was the second person that season to have stayed in a hunting camp that can host three hunters at a time, and I was alone for most of the 10 days I was there. The locals were very glad to see me and I received the best of care and attention. I also found it easy to get quota on anything I wanted to shoot, since no one else was shooting anything!
I'm comfortable enough that I'm taking my own advice and heading back for a third straight year (I'm lucky, I know) to hunt elephant this July.
I would say don't stay away. If you take reasonable precautions - the same as you'd take in any less developed country, and refrain from expressing views on the local political situation, you will have a great hunt. Zimbabwe PH's are likely the best trained in Africa, and the shooting is as close as you're likely to get to the old safari days. Very few fences - in Matetsi only a dirt road (and the Botswana Defence Forces on the other side!) lets you know that you're on an international border. The wildlife is abundant, and the money you spend will help local communities or the Parks Service, both of which desperately need support.
Not too many places you can enjoy yourself as much as Zimbabwe while doing good at the same time!
Good luck.