Google added an on-screen keyboards to Google Translate. You'll notice a small keyboard icon in the bottom corner of the text input box. Click this to open a virtual keyboard for the selected input language. You can either click letters on the on-screen keyboard, or type using your real keyboard while on-screen keyboard is visible.
Some languages such as Vietnamese and Armenian have more than one popular layout for local keyboards. The on-screen keyboards support multiple layouts too, and you can switch between these layouts by clicking on the arrows at the top of the on-screen keyboard.
To close the on-screen keyboard, simple click the small keyboard icon again.
Some of you may be familiar with "Phonetic typing" feature - for a few languages such as Arabic, you can type a word as it would sound in English (e.g. "marhaban"), and see the letters transformed to Arabic before being translated. The new on-screen keyboards don't interfere with phonetic typing for languages that support both -- when the keyboard is open, phonetic typing will be disabled.
On-screen keyboards is avaialbe for these languages: