Drop Old Browser Workaround?

More and more, the protection preventing <script> tags from being read as
text in old browsers is being left out.--


<script type="text/javascript">
some code . . .
</script>

rather than

<script type="text/javascript">
<!--
some code . . .
// -->
</script>


For instance, Google (http://www.google.com/) uses the protection but
Amertrade (http://www.tdameritrade.com/welcome1.html) does not.

Older browsers are increasingly very hard to keep going, update and reloaded
onto a system. Do you folks think it is safe to move on and drop the
protection?

TIA,

tj