I've been reading in research for the timeline I'm working on. In Christopher Clark's rather excellent book Iron Kingdom (The Rise and Downfall of Prussia 1600-1947) I encountered a brief mention that Saxony and Austria had agreed that Saxony would be ceded a strip of Silesia to create a common border between the Electorate of Saxony and Poland, which were in a personal union at the time, in exchange for Saxony's support of Maria Theresa's succession to the Habsburg thrones following Charles VI's death. Saxony was involved (initially) on the anti-Austrian side of the War of the Austrian Succession, which I believe made it rather difficult to press the claim in the wake of Prussia's annexation of most of Silesia.
What might the ramifications of Saxony successfully being granted part of northern Silesia? Clark suggests that such an action would allow Saxony to permanently outstrip Prussia in terms of power and influence in Germany, which I can believe. Silesia was a fairly industrialized province that was quite valuable to Prussia's rise to Great Power-dom after all.