I do this, but it's not done for you in SQL Server. I capture mdf,ldf and data sizes every day - from this I produce reports on database growth and as I have several years of data I can then forward predict growth for trending, I currently predict 3 years ahead.
so - create a table to collect the data, schedule a job and write some reports. as they say in Meerkovo "simples!"
[font="Comic Sans MS"]The GrumpyOldDBA[/font]
www.grumpyolddba.co.uk
http://sqlblogcasts.com/blogs/grumpyolddba/