After the high excitement of 2010-11, it’s been a bad year for the tablet so far. In the wake of the launch of the first iPad ‘ one of the only form factors Apple really did pioneer ‘ there were forecasts that touchscreen slates were going to replace PCs in short order. But while the device has been a factor in eroding the dominance of the PC in the past couple of years, many other designs are doing the same, some of them far more PC-like (ultrabooks, Chromebooks, hybrids, large smartphones etc). The iPad was a weak point in Apple’s most recent results, and this week Morgan Stanley said it had slashed its forecast for tablet growth this year, from…