Nobody really bothers about a Text to Speech engine and the updates to that unless it concerns a language support for your local language. This is exactly why, the latest update would be of great importance, if you are from India and have keen interest in hearing your phone read out hindi content in the best possible robotic voice.
You will need to update the Text to Speech engine right from the Google Play Store. The update will also see support for Indonesian being added on. Sadly, even though the support for text to speech has been added, there is no support yet for a voice recognition for Hindi. The language pack will only have a female voice on it, and therefore will not give too many options in case you do not like shrill female voices.
The update shows that India is an extremely important market for Google, while Indonesia already is the fourth largest country when it comes to active Android devices in usage. In case you do not wish to wait for the update to hit your device via Google Play, you can also download the apk file from here and simply over write the existing one. The apk is protected by an encrypted signature so you would not have a problem with malfunctioning apks.