Yeah, some of the new anime series are shorter now
wrapping up in 13 episodes only.  Some of them
are forced to cut short due to the low ratings.
Even though some new series are shorter nowaday,
but it means there're more series than before.
In the old days, the same time slot can only fit 
two series in one year, now it can fit 4 
different series :)  
On the other hand, some high rating series will 
keep going on for a long time, like Detective 
Conan, Young Cases Files of Kindachi, and
Pokemon...etc.  By the way, there're more kiddy
shows filling the Japanese TV now, it seems more
anime studios are going to be targeting back on
the children market.  That means...there won't
be too many shows for older audiences, such as
Escaflowne or Vampire Princess Miyu.