Giridhar has posted some very interesting data on this year's GATE in chemical, civil and electronics engineering, and computer science. One thing that strikes you right away is that the averages (or at least, the medians) are very low indeed. Even at the 75th percentile, for example, the marks have fallen to around 20/100.
Inspired by his post (and with his helpful hints -- thanks Giridhar!), I went and collected some data for the metallurgical engineering (MT) paper that our department (Materials Engineering) draws most of its students from. I have posted a quick (and incomplete) analysis over at Materialia Indica (much like the one I did for JEE-08). Compared to Giridhar's numbers for other disciplines, the average (or, the median) in the MT paper of GATE-09 is far better. it's around 35/100.
Finally, you really ought to go read this chemical engineer's candid take on this year's GATE in his field.