I may be mistaken but it sounds as if your problem is transaction confirmation time, not block solve time.
As already mentioned blocks are solved about every 10 minutes on average. This has always been the case irrespective of the number of miners. The mining difficulty is automatically changed each fortnight to ensure 10 minutes stays around the average solve time.
Transaction confirmation time can be a very different matter. It is up to a block miner to decide whether to include your transaction in the block they are mining.
If you don't include a mining fee, and the Bitcoins in the transaction have only recently been moved. it can take a while for the transaction to be confirmed in a block. Several hours are possible. The miners will normally include transaction which are 'high priority' or which include fees. For non fee transactions it just depends on the miner - in the long term it is in the miners interest to encourage fee paying.
If you need the transaction to go through quickly ensure you have included a mining fee. I think the default mining fee is currently 0.0001 BTC.
See
http://bitcoinfees.comhttps://en.bitcoin.it/wiki/Transaction_fees if you want the details.