This was removed IIRC. As the estimated time changed every block as the target changed, people got confused/angry. They thought it was broken and got disheartened. They didn't understand what it represented.

You can calculate it yourself, there are instructions in the wiki

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If you divide 100% by the target value you'll get the portion of coins that was used for mining that block. (Note: Because blocks are generated once per minute, you should take an average value of these targets, since they fluctuate from minute to minute)

For example, if the average target value is 400%, then only 100/400 = 25% of coins are mining blocks.Now you can calculate an approximate value of how many blocks you might create per day by multiplying the number of coins you own by the absolute value of the target (e.g. the absolute value of 400% = 4), and then divide by 694,444.

For example, if you have 50,000 Nxt coins and the average value is 400%, you could forge 0.288 Nxt blocks per day, which translates to one block every 3 or 4 days.
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Source: http://wiki.nxtcrypto.org/wiki/FAQ#Forging