One of the biggest problems in theology is that the NT, and even theologians, do not use words in one precise way, nor set up single schemes that exclude all others.
I would maintain that Wright is essentially right about Paul, but is probably being unfair to Calvin. But to justify this we need to look at both in more detail than anyone here has done so far.
Paul says in Romans that we are justified by faith. He doesn't say that Christ's righteousness is imputed to us, but rather that our faith is reckoned by God as righteousness. What does righteousness mean? The general definition, I think, is doing the right thing. For Christians that means doing what God requires. Paul's point is that for us, God accepts faith as satisfying his requirement. We are genuinely righteous when we have faith, because that's what God is looking for. He is not looking for works of the Law.
However there's a second stage of the argument which I'm not sure Wright makes so clearly. Paul normally speaks of righteousness as coming from faith, but in a few places he uses it more conventionally, for behavior that God approves. So Rom 14:4, 2 Cor 6:7. Paul certainly doesn't think that having faith ends God's expectations for us, and that there are no expectations for behavior. So if you think righteousness means doing what God demands, he does demand that Christians lead an obedient life. I think Jesus uses the term righteousness in this sense, as does Paul a couple of places. If that's right, that the use of righteousness in Rom 4 and 5 is referring to what God demands in a specific context, the context being what God demands in order to recognize us as one of his, i.e. it's the righteousness that is associated with justification. And in that context, what God demands is faith, so he reckons our faith as righteousness. And that's roughly the definition of righteousness that Wright uses: righteousness for him is being in good standing with God. But that doesn't exhaust the contexts in which righteousness is used.
So how about Calvin? Calvin's position on justification in the Institutes is more complex than often described. His basic concept is that we are righteous because God has forgiven us. If he has forgiven us, than none of our sins count against us, and we can be considered as having done what God requires. He cites Luke 18:14. I believe this is a fair position, which agrees with Jesus. Jesus demands obedience, but he is also clear that God is happy to forgive us when we repent. He says that the tax collector is justified, and I think he would also consider a person who lives a generally faithful life but repents when they need to as righteous, though Jesus doesn't use righteous as often or in as technical a way as Paul does.
But Calvin also deals with Paul. He also recognizes Paul's concept of the righteousness that is based on faith. But he goes beyond that to make explicit what Paul leaves implicit: that faith justifies because it unites us with Christ, and that through this we receive Christ's obedience. This is Rom 6. It's certainly consistent with Paul's thought. But Paul never actually says that we are justified by Christ's righteousness or obedience. When he uses term "imputed" (though it's normally translated "reckoned" by the NRSV) he's talking about faith, not Christ's righteousness. But the connection is there, and Calvin brings it out. We are not justified simply by God counting Christ's obedience as ours, independent of any connection with us. Rather, we are justified by faith, and both Calvin and Paul say that faith is participation in Christ. So we actually participate in his obedience, even though it always remains in some sense external to us. Since faith is participation in Christ, in the end we are justified (reckoned righteous) due to Christ's obedience.
The problem I have with the usual statement that Christ's obedience is imputed to us is that it short-circuits this account, and implies a kind of legal fiction. I think it's safer to say, with Paul, that our faith is reckoned as righteousness, and then look at the implications of faith.
Here's what Calvin says about how justification works:
"I acknowledge that we are devoid of this incomparable gift until Christ become ours. Therefore, to that union of the head and members, the residence of Christ in our hearts, in fine, the mystical union, we assign the highest rank, Christ when he becomes ours making us partners with him in the gifts with which he was endued. Hence we do not view him as at a distance and without us, but as we have put him on, and been ingrafted into his body, he deigns to make us one with himself, and, therefore, we glory in having a fellowship of righteousness with him." (Institutes 3.11.10)
There is, I think, a difference between Calvin's "fellowship of righteousness", echoing Rom 6, and a purely legal imputation of Christ's righteousness.
I think Wright would benefit by looking at Calvin's treatment, but he is primarily a NT scholar, not a Reformation expert. I don't think Wright's work, particularly with later clarifications, contradicts all of this though.