What database platform better at scaling? I am planning a for a database that i expect will be very big in terms of number of records rather than tables and batabases.  My Question is what product (i.e, SQL 2008, Cassandra, Azure) handles scaling better? 

I expect that there will be 100k or so records will be added everyday, It should easily retrieve a single row and a batch of them.

The app will crawl the web and for each word in a dictionary will find the same word used in different sentences and record them to a database.
The developers are mainly .net oriented but they are fluent in C/C++ as well and because this is a academic project anything is basically affordable.

One platform/product per answer please.
Any of the big RDBMS systems or NoSQL systems can handle that sort of data load.  Back in 2002 I had a database table with 1B records in it that got more than 100k records a day, and that was running SQL Server 2000.  The systems today are much faster (both the hardware and the software) and should be able to handle that load going in with no problem.  The big problem becomes getting the data out, and having the data indexed properly to find it based on how you want to search.  And having enough memory to load the data into cache to find it faster.