The capacity specs are listed in books online. to briefly summarise:
Database size 524,258 terabytes
Files per database: 32,767
File size (data): 16 terabytes
Rows per table: Limited by available storage
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability