I can say that a few of us have indeed tried various forms of communication, with no success so far. There is a precedent for the qualification being this late (in 2012, the two competitions were held 4 and 5 weeks before the international championships began) so I wouldn't abandon hope yet, but given the WSC/WPC's registration timeline, if nothing is announced in the next week or so then my gut is that it doesn't look likely.

I'd also like to say (in a public forum) that even if there is a precedent, it's a pretty lousy precedent. I feel that the shorter the period of time between the qualifier and competition, the more it discriminates against potential participants without large disposable incomes, who can't book expensive last minute plane tickets and take a week off from work on short notice. I was thankful that last year's qualifier was early enough for me to book the London flights with frequent flyer miles. Though maybe this has never been a problem for the A qualifiers (I've never made it past the B team despite making the top five in eight of the last nine years), so I may trumpeting for a cause that doesn't exist.

In any case, Nick has a pretty thankless job in putting the USPC and USSC together, as they're a ton of work and the puzzle quality is consistently high. I would totally understand if it's become something he doesn't have the time to deal with, but if that's the case, I hope he looks for someone to take over for him instead of just letting it die.

If there simply wasn't going to be a USPC this year, I assume they'd be deciding a team based on past performance, the GP, and so on, and willwc would have already have gotten an invitation or something.
Assuming there is a USPC, it does have to be in the next few weeks, so I'm sort of assuming we'll hear something soon.
In the past, there has never been much advance notice -- they tend to send an email around and update the webpage a week or so before the event. I have always wished we had more advance notice.
And I agree that since the top qualifiers are going to have to arrange international travel, possibly ask for a couple of days off work, and so on, having the qualifiers earlier is better (not that I'm worried personally, having barely cracked the top 25).

I called Will Shortz's public phone and left a message asking about a 2015 USPC (without being too naggy) and I also emailed Nick Baxter. I really hope it's not cancelled this year :(

Good news everyone! I just received word from Will Shortz-- he got in contact with Nick, we are still having a USPC this year! woohoo! The contest is planned for early September. See you all there!

I got mail from Nick regarding this championship as below
Team qualifying:
U.S. Puzzle Championship - Saturday, Sept. 5
Sudoku Team Qualifying Test - Sunday, Sept. 6

Please visit the USA website for further details:
U.S. Puzzle Championship: http://wpc.puzzles.com/uspc2015 (update Aug 31)
Sudoku Team Qualifying: http://wpc.puzzles.com/ussq2015 (update Aug 31)