These are the increased numbers for Office 2k7 from 2k3:
The "Big Grid" and Increased Limits in Excel 2007
The Excel 2007 "Big Grid" increases the maximum number of rows per worksheet from 65,536 to over 1 million, and the number of columns from 256 (IV) to 16,384 (XFD).
If you work with large workbooks, you probably have found that the increased memory capacity of recent versions of Excel has meant that you hit some of the other Excel specification limits more frequently. Excel 2007 includes many changes to these limits to accompany the large increase in row and column capacity.
* Memory Usable memory for formulas and pivot caches is increased to 2 gigabytes (GB) from 1 GB in Microsoft Office Excel 2003, 128 megabytes (MB) in Microsoft Excel 2002, and 64 MB in Microsoft Excel 2000.
* Smart recalculation limits The dependency limits that enable smart recalculation rather than full calculation are now limited only by available memory rather than 8,000 cells dependent on a single area and 64,000 areas having dependencies.
* Array formulas Full column references are now allowed, and the limit on array formulas referring to another worksheet is increased from 65,000 to available memory.
* PivotTables Maximum rows displayed in a PivotTable report is 1 million. Maximum columns displayed in a PivotTable report is 16,000. Maximum number of unique items within a single Pivot field is 1 million. Maximum number of fields visible in the Fields list is 16,000.
* Sorting Levels increased from 3 to 64.
* AutoFilter Drop-down list length changed from 1,000 items to 10,000 items.
* Maximum formula length Increased from 1,000 to 8,000.
* Formula nesting levels Increased from 7 to 64.
* Arguments in a function Increased from 30 to 255.
* Conditional formats per cell Increased from 3 to available memory.
* Unique cell styles in a workbook Increased from 4,000 to 64,000.
* Unique colors per workbook Increased from 56 to 4.3 billion.
* Characters in a cell that can be displayed and printed Increased to 32,000.