Tablets are going to face some trouble in 2011 but will ultimately marginalize netbooks, DisplaySearch estimated on Wednesday. Researchers expected a "hitch" in tablet deliveries through the spring and summer as many companies wouldn't be sure how to sell their first tablets while seeming like a viable contender against the iPad 2. It wouldn't be until the second half of the year that demands would be clearer and rivals could try attacking the market in earnest.