Not necessarily. This is Blago's lawyer who is saying this. All this means is that a motion has been filed to exclude the wire taps as evidence. A judge must rule on the motion and that won't happen straight away. I expect the evidence will not be excluded. The FBI isn't completely populated by fools. They usually know what they are doing as far as procedure goes. Especially in a high profile case like this.
The FBI has a long tradition of illegal wiretapping, going back at least to the 1960s and COINTELPRO. It’s much easier for them to get legal authority nowadays, but old habits may die hard.
Wonder how much that will cost him?