Google has released an update to Gmail for Android 2.3, but unfortunately that means only Nexus S owners have a chance to use it, unless you own a Nexus One that has been upgraded to Android 2.3. The update simplifies the process of selecting and copying text to the clipboard and adds support for colored labels.
On Android phones not running Android 2.3, the process for selecting text involves pressing Menu, More, Select Text. With the update on Android 2.3 to select text you press and hold on the screen until the selection cursor appears, then slide your finger over the text to select it, move the beginning and ending markers to correct the selection if necessary, and finally tap the selected text to copy it to the clipboard.
According to AndroidCentral, the update also adds support for synchronization of label colors in Gmail, however, I have found that label colors are also syncing to my Nexus One that is running Android 2.2. I had not been using colored labels, so I had to enable it in Gmail from my PC in order to test this feature. After I synchronized the email on my Nexus One, color labels appear on it just as they do on my Nexus S.