Hi there.
I'm originally from Zimbabwe and returned last year October for a holiday. I was self driving and drove from Harare through to Mana Pools National Park without any problems. I haven't been to Vic Falls and Hwange for ages, but I still stay in contact with people in the Falls area and they are all safe and sound. I read a report in Travel Africa Magazine of a journalist who recently travelled around Zim for a month to see how safe it was for tourism and it was all positive.
Hope that helps.