Well, since US debt has never been downgraded before, we don’t know. However, it’s very possible that it will make credit more expensive and harder to come by. Since most business acquisitions involve, some amount of borrowing, it may negatively impact the value and salability of your company.
On the bright side: more people are looking for investment alternatives. Stocks, bonds, and cash are all doing poorly now. Some people will reason it’s better to invest in buying a going business than in more traditional investments.