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)