Apple may be celebrating another successful iPhone rollout today, but it's a far different story for Blackberry. The company said it will lay off 4,500 employees, or 40% of its global workforce, as it reports a nearly $1 billion second-quarter loss a week earlier than expected. The stock dropped 23% to $8.11 on the news. The Canadian company expects to post a staggering loss of $950 million to $995 million for the quarter, including a massive write-down of the value of its inventory because of increasing competition. See TheStreet for more details. (More BlackBerry stories.)