The following is the answer for Eclipse 3.7
I am not sure whether this is a plugin or RCP. But the following XML should work if your are testing a Plugin. Note the attribute
productId="org.eclipse.platform.ide"
Hence the extension should look like the following
<extension
point="org.eclipse.ui.splashHandlers">
<splashHandler
class="sample6.splashHandlers.InteractiveSplashHandler"
id="sample6.splashHandlers.interactive">
</splashHandler>
<splashHandlerProductBinding
splashId="sample6.splashHandlers.interactive"
productId="org.eclipse.platform.ide">
</splashHandlerProductBinding>
</extension>