This rumor is laughable. There's only one player to trade up for and he's Byron Leftwich, not Andre Johnson. Just the same, I don't think the Cardinals will be trading up. I think they will be happy with Leftwich, Suggs or Williams at #6 and all three could very well be available at that spot, therefore no need to trade up.
The other thing that's curious about this rumor is that the Texans have yet another plethora of draft picks this year...thanks to the league's ridiculously generous new franchise draft pick reward policy. In fact, the NFL ought to look closely at this policy. I can see awarding a new franchise extra draft picks the year it enters the league, but with free agency the way it is...it's not right to give the Texans or anyone else extra draft picks in the second year. Heck, the Texans didn't even have the worst record in the NFL its inaugural season. And Carolina made it to the NFC Championship in what its second or third year? This isn't right.