According to Business Insider an analyst for Piper has been saying that they expect no iPhone announcement at WWDC, but rather an influx of news on the upcoming Snow Leopard. Analyst Gene Munster was quoted as saying:
The current prices of AT&T’s plans are of the astronomical sort. I admit, the cost is so high it has made me consider going the way of the Palm Pre, should it be significantly less. The typical iPhone plan starts at $75 and goes over $150 from there.