I just read the transcript of the oral arguments in TC Heartland, and my initial impression is that Kraft—the respondent/one who wants to uphold the current venue interpretation—is starting out in a very difficult situation. Take, for example, this exchange (emphasis added in bold):
JUSTICE BREYER: (Speaking of the legislative history) But did it say, if you pass this, don't worry about getting rid of 1400, because this gets rid of it? I mean, did they say anything like that at all?
MR. JAY: No. Because 1400 still serves a function.... But... I think it's important to note that under our view, 1400(b) does do work. It is the venue statute. So you have to show either that the defendant reside—all defendants reside there, or all defendants are subject to suit there under the other—under the second half. That's different from what the general venue statute provides, which, for example, can base venue on the residence of only one defendant. There is significance; there is work left to be done for 1400(b).
Translated from legalese, Mr. Jay (for Kraft, the respondent) is arguing that his client's preferred interpretation doesn't simply make 1400(b) (the patent-specific venue statute) irrelevant.
But the fact that he is needing to argue this point is problematic for his case.
Prior coverage here.