There is following footprint increase (regression) first appeared in fx2.1-controls-scrum build b92:

NodeMemory.TreeItem 63,200 => 40,000
NodeMemory.TreeView 170 => 160

The same regression exists in fx2.1-graphics-scrum-b136.

I can easy reproduce it. Steps to run TreeItem:
> java -Xms48m -Xmx48m -cp "..." jrockit.bm.Main nodememory.bm.TreeItemBenchmark -i 1 -tr 240 -wt 0 -render true -allocCnt 2000


fx2.1-controls-scrum-b92 contains the following list of changes.
 Automated merge with ssh://jfxsrc.us.oracle.com//javafx/2.1/scrum/controls/jfx/rt (detail)
 RT-17522: [ListView] Adding element on focus position don't make it move. (detail)
 [TEST ONLY] Unit tests for RT-17522 (detail)
 RT-18132: Anomaly with selectedItemProperty in ListView Control (detail)
 RT-17974: SHIFT-SPACE does not correctly creates continuous selection (ListView, TreeView, TableView) (detail)
 RT-17456: TreeView: selection with MOUSE_PRESSED (detail)
 Added 91 unit tests for ComboBox, and fixed a couple of minor bugs that were identified. (detail)
 RT-18200: ComboBox should provide a constructor that takes an ObservableList of items (detail)
 RT-18199: ComboBox is lacking an onAction event (detail)
 [DOCS ONLY] Improved javadoc for ComboBox and ComboBoxBase classes. (detail)
 RT-18179: [Editable ComboBox] After typing a text and pressing Enter text disappears from the textfield (detail)
 RT-18177: [Editable ComboBox] Hovering mouse over the ComboBox should not change color of the text (detail)
 Automated merge with ssh://jfxsrc.us.oracle.com//javafx/2.1/scrum/controls/jfx/rt (detail)
 RT-18129: [ComboBox] Scrollbar should appear if the active list contains more items than defined max (detail)
 RT-18151: [ComboBox] Clicking the ComboBox should close the active list if it is open (detail)
 Partial patch for RT-18026: Evaluate TODOs in code, either removing or filing issues as appropriate (detail)

Need to find the reason and file RT issue if needed.