More clarification on FAQ answers.

www/index.html

@@ -49,7 +49,7 @@
         the Bitcoin network.  It can only be changed if every user of the
         network decided to change it as part of a hard fork.  One of Bitcoin's
         core offerings is its fixed and unchangable monetary policy, so it's
-        exceedingly unlikely that it is going to be changed.
+        <em>exceedingly unlikely</em> that it is going to be changed.
         <br/><br/>
         The reward function (in Bitcoins) is
         <code>r(h) = 50 / (2 ** floor(h / 210000))</code>, where h is block height.
@@ -62,7 +62,9 @@
       <p>
         A: Since mining is a probabilistic process, it's impossible to predict
         when new blocks will be mined.  <em>On average</em>, new blocks are
-        mined every 10 minutes, but this can vary a lot.
+        mined every 10 minutes, but this can vary a lot.  So it's hard to
+        predict <em>exactly</em> when block number 630000 will be mined, but all
+        answers will converge when the time comes.
       </p>
 
       <p>