Ok, well, for example one can look at the estimated USD transaction volume maintained by blockchain.info:
http://blockchain.info/charts/estimated-transaction-volume-u... which went, over 1 year, from $0.5M to $10M transacted per day (it uses an algorithm to attempt to ignore the change of a transaction, hence "estimated"). A fraction of this volume is from people just moving BTC between their different wallets. It is impossible to estimate how large this fraction is. But the reasonable assumption that
people are not artificially trying to game this chart by moving coins around leads to the reasonable conclusion that the volume of real transactions is increasing as well.
You can look at the USD volume traded on the top Bitcoin exchanges which went, over 1 year, from $200-300k to $1.0-2.5M per day: http://blockchain.info/charts/trade-volume
You can look at Silk Road, who went, over 2 years, from zero to $2 million/month of Bitcoin revenues: http://arstechnica.com/tech-policy/2012/08/study-estimates-2...
A Bitcoin casino went, over 6 months, from zero to $0.5 million profits (in bitcoins): http://arstechnica.com/business/2013/01/bitcoin-based-casino...
Bottom line, all the indicators point to increased Bitcoin spending.