Underpromise & over-deliver vs over-promise & under-deliver. When you over-promise you're raising expectations that you can't possibly meet, but when people have nothing to compare the product to, e.g. the first iPhone/iPad and it's launching in days/weeks, not some ethereal date subject to change a year or more away. Remember that HP-Windows 7 "iSlate" Ballmer showed off? Vaporware. Why even bother telling lies if it's only going to inevitably disappoint? Maybe they are just naive?