> Looking at the Tiobe list for concreteness [...] At 17 (Groovy)
No need to consider whether Groovy follows the trend or not. Tiobe gives a history of all Top 20 languages as a graph, just click on the language name in the top 20 chart. Groovy's ( http://www.tiobe.com/index.php/paperinfo/tpci/Groovy.html ) shows the most volatile movement in the rankings (e.g. it just rose from #82 to #17 in a mere 12 months), and Tiobe's comment "Scala might gain a permanent top 20 position soon" is probably a back-handed dig at the likely impermanence of Groovy's top 20 position. That language is being actively fiddled through the popularity rankings.
No need to consider whether Groovy follows the trend or not. Tiobe gives a history of all Top 20 languages as a graph, just click on the language name in the top 20 chart. Groovy's ( http://www.tiobe.com/index.php/paperinfo/tpci/Groovy.html ) shows the most volatile movement in the rankings (e.g. it just rose from #82 to #17 in a mere 12 months), and Tiobe's comment "Scala might gain a permanent top 20 position soon" is probably a back-handed dig at the likely impermanence of Groovy's top 20 position. That language is being actively fiddled through the popularity rankings.